These are the median wait times for exercises that were mentorees during the 4 weeks preceeding 6th July 2019.

ballerina: hello-world-service: 7 days
ballerina: greeting-service: 9 days
ballerina: service-invocation: None mentored
ballerina: legacy-service-client: None mentored
ballerina: calculator-service: None mentored
ballerina: order-management: None mentored
ballerina: service-composition: None mentored

bash: two-fer: about 21 hours
bash: error-handling: about 2 hours
bash: raindrops: 2 days
bash: hamming: 4 days
bash: acronym: 2 days
bash: armstrong-numbers: 6 days
bash: pangram: 4 days
bash: bob: 18 days
bash: scrabble-score: 5 days
bash: grains: 8 days
bash: luhn: None mentored
bash: atbash-cipher: None mentored

c: isogram: 5 days
c: word-count: 5 days
c: hamming: 8 days
c: grains: 13 days
c: beer-song: 13 days
c: difference-of-squares: 5 days
c: binary-search: 9 days
c: roman-numerals: 11 days
c: allergies: 7 days
c: atbash-cipher: 7 months
c: phone-number: None mentored
c: clock: None mentored
c: sieve: 6 days
c: robot-simulator: None mentored
c: pascals-triangle: None mentored
c: binary: 7 days
c: palindrome-products: 9 days
c: scrabble-score: None mentored
c: queen-attack: None mentored
c: linked-list: None mentored

ceylon: leap: None mentored
ceylon: hamming: None mentored
ceylon: sieve: None mentored
ceylon: rna-transcription: None mentored
ceylon: anagram: None mentored
ceylon: largest-series-product: None mentored
ceylon: matching-brackets: None mentored
ceylon: react: None mentored

cfml: leap: 3 months
cfml: raindrops: None mentored
cfml: scrabble-score: None mentored
cfml: difference-of-squares: None mentored
cfml: secret-handshake: None mentored
cfml: space-age: None mentored
cfml: acronym: None mentored
cfml: rna-transcription: None mentored
cfml: pangram: None mentored
cfml: hamming: None mentored

clojure: armstrong-numbers: about 1 month
clojure: two-fer: about 21 hours
clojure: reverse-string: 2 months
clojure: bob: 3 months
clojure: rna-transcription: about 2 months
clojure: run-length-encoding: None mentored
clojure: isbn-verifier: None mentored
clojure: word-count: None mentored
clojure: anagram: None mentored
clojure: say: None mentored

coffeescript: bob: None mentored
coffeescript: word-count: None mentored
coffeescript: accumulate: None mentored
coffeescript: binary: None mentored
coffeescript: anagram: None mentored
coffeescript: trinary: None mentored
coffeescript: hexadecimal: None mentored
coffeescript: triangle: None mentored
coffeescript: luhn: None mentored
coffeescript: binary-search-tree: None mentored

common-lisp: two-fer: 1 day
common-lisp: hamming: about 6 hours
common-lisp: leap: about 3 hours
common-lisp: bob: about 18 hours
common-lisp: rna-transcription: about 17 hours
common-lisp: word-count: 1 day
common-lisp: beer-song: about 23 hours
common-lisp: anagram: about 23 hours
common-lisp: roman-numerals: 8 days
common-lisp: sieve: 1 day

coq: rna-transcription: None mentored
coq: tautology: None mentored

cpp: leap: about 2 hours
cpp: reverse-string: about 1 hour
cpp: space-age: about 5 hours
cpp: triangle: about 7 hours
cpp: grains: about 2 hours
cpp: raindrops: about 8 hours
cpp: pangram: about 3 hours

crystal: hamming: None mentored
crystal: gigasecond: None mentored
crystal: rna-transcription: None mentored
crystal: bob: None mentored
crystal: raindrops: None mentored
crystal: leap: None mentored
crystal: triangle: None mentored
crystal: difference-of-squares: None mentored
crystal: pangram: None mentored
crystal: largest-series-product: None mentored

csharp: two-fer: about 10 hours
csharp: leap: 1 day
csharp: gigasecond: about 20 hours
csharp: resistor-color: about 12 hours
csharp: space-age: 1 day
csharp: high-scores: about 11 hours
csharp: hamming: 1 day
csharp: nucleotide-count: 1 day
csharp: robot-name: about 12 hours
csharp: allergies: about 13 hours
csharp: grade-school: 3 days
csharp: rotational-cipher: 3 days
csharp: circular-buffer: about 16 hours
csharp: clock: 2 days
csharp: bob: about 23 hours
csharp: matching-brackets: 1 day
csharp: spiral-matrix: 4 days
csharp: tournament: 2 days
csharp: variable-length-quantity: 2 days
csharp: dominoes: 5 days
csharp: forth: 1 day

d: leap: None mentored
d: gigasecond: None mentored
d: rna-transcription: None mentored
d: raindrops: None mentored
d: bob: None mentored
d: etl: None mentored
d: hamming: None mentored
d: nucleotide-count: None mentored
d: robot-name: None mentored
d: difference-of-squares: None mentored

dart: two-fer: about 1 month
dart: leap: 10 days
dart: scrabble-score: about 2 months
dart: armstrong-numbers: about 2 months
dart: difference-of-squares: 22 days
dart: word-count: None mentored
dart: bob: None mentored
dart: space-age: about 2 months
dart: hamming: 2 days
dart: gigasecond: None mentored
dart: raindrops: None mentored
dart: rna-transcription: None mentored
dart: anagram: None mentored
dart: pascals-triangle: None mentored
dart: isbn-verifier: None mentored
dart: binary-search-tree: None mentored

delphi: two-fer: 5 days
delphi: leap: None mentored
delphi: gigasecond: None mentored
delphi: resistor-color: None mentored
delphi: space-age: None mentored
delphi: high-scores: None mentored
delphi: hamming: None mentored
delphi: nucleotide-count: None mentored
delphi: robot-name: None mentored
delphi: allergies: None mentored
delphi: grade-school: 1 day
delphi: rotational-cipher: None mentored
delphi: circular-buffer: None mentored
delphi: clock: None mentored
delphi: bob: None mentored
delphi: matching-brackets: None mentored
delphi: tournament: None mentored

elisp: two-fer: about 17 hours
elisp: bob: 2 days
elisp: hamming: about 2 hours
elisp: anagram: about 10 hours
elisp: leap: about 23 hours
elisp: rna-transcription: about 10 hours
elisp: roman-numerals: 5 days
elisp: word-count: 1 day

elixir: rna-transcription: about 18 hours
elixir: word-count: 1 day
elixir: roman-numerals: 1 day
elixir: bob: 1 day
elixir: beer-song: 1 day
elixir: robot-simulator: 1 day
elixir: list-ops: 1 day
elixir: markdown: 1 day
elixir: bank-account: 1 day
elixir: zipper: 2 days
elixir: bowling: 2 days
elixir: forth: 2 days

elm: two-fer: about 20 hours
elm: bob: 8 days
elm: twelve-days: 10 days
elm: leap: 2 days
elm: triangle: 5 days
elm: space-age: 7 days
elm: scrabble-score: 8 days
elm: sum-of-multiples: 2 days
elm: accumulate: 7 days
elm: anagram: None mentored
elm: grade-school: None mentored
elm: raindrops: 11 days

erlang: two-fer: None mentored
erlang: leap: 3 days
erlang: accumulate: 4 days
erlang: collatz-conjecture: 2 days
erlang: raindrops: None mentored
erlang: rna-transcription: 12 days
erlang: bob: 8 days
erlang: strain: 11 days
erlang: hamming: None mentored
erlang: space-age: 12 days

factor: leap: None mentored
factor: two-fer: None mentored
factor: isogram: None mentored

fortran: bob: None mentored
fortran: hamming: None mentored
fortran: rna-transcription: None mentored
fortran: raindrops: None mentored
fortran: difference-of-squares: None mentored
fortran: pangram: None mentored

fsharp: leap: about 2 hours
fsharp: bob: about 17 hours
fsharp: sum-of-multiples: about 18 hours
fsharp: two-fer: about 2 hours
fsharp: space-age: 3 days
fsharp: raindrops: 3 days
fsharp: accumulate: about 9 hours
fsharp: grade-school: 14 days
fsharp: beer-song: 9 days
fsharp: queen-attack: about 3 hours
fsharp: kindergarten-garden: 1 day
fsharp: clock: about 3 hours
fsharp: robot-simulator: about 20 hours
fsharp: allergies: about 2 hours
fsharp: ocr-numbers: 9 days
fsharp: tree-building: 18 days
fsharp: pig-latin: None mentored

gnu-apl: leap: None mentored
gnu-apl: hamming: None mentored
gnu-apl: rna-transcription: None mentored
gnu-apl: raindrops: None mentored
gnu-apl: difference-of-squares: None mentored
gnu-apl: pangram: None mentored

go: two-fer: about 16 hours
go: hamming: 2 days
go: raindrops: about 3 hours
go: scrabble-score: 2 days
go: isogram: 3 days
go: difference-of-squares: 3 days
go: luhn: 4 days
go: grains: 1 day
go: clock: 3 days
go: parallel-letter-frequency: about 18 hours
go: tree-building: 3 days
go: robot-name: 6 days
go: tournament: 3 days
go: twelve-days: 2 days
go: matrix: 5 days
go: error-handling: 8 days
go: bank-account: 1 day

groovy: two-fer: 3 days
groovy: hamming: 1 day
groovy: gigasecond: 1 day
groovy: scrabble-score: about 15 hours
groovy: difference-of-squares: about 5 hours
groovy: secret-handshake: 1 day
groovy: matrix: 1 day
groovy: triangle: 2 days
groovy: rotational-cipher: 1 day
groovy: saddle-points: 1 day
groovy: flatten-array: 3 days
groovy: word-count: 1 day
groovy: robot-name: 3 days
groovy: binary-search: 1 day
groovy: bank-account: 1 day
groovy: linked-list: 1 day

haskell: leap: 1 day
haskell: space-age: about 17 hours
haskell: pangram: 3 days
haskell: bob: 3 days
haskell: collatz-conjecture: 2 days
haskell: rna-transcription: 10 days
haskell: nucleotide-count: about 21 hours
haskell: sum-of-multiples: 1 day
haskell: grains: 9 days

haxe: bob: None mentored
haxe: leap: None mentored

idris: rna-transcription: None mentored
idris: leap: None mentored
idris: hamming: None mentored
idris: accumulate: None mentored

java: two-fer: about 6 hours
java: hamming: 3 days
java: gigasecond: 7 days
java: scrabble-score: 7 days
java: difference-of-squares: 9 days
java: secret-handshake: 6 days
java: matrix: 11 days
java: triangle: 7 days
java: rotational-cipher: 7 days
java: saddle-points: 8 days
java: flatten-array: 6 days
java: word-count: 3 days
java: robot-name: None mentored
java: binary-search: 4 days
java: bank-account: 10 days
java: linked-list: 1 day

javascript: two-fer: 6 days
javascript: resistor-color: 4 days
javascript: resistor-color-duo: 16 days
javascript: gigasecond: 9 days
javascript: rna-transcription: 5 days
javascript: space-age: 10 days
javascript: pangram: 6 days
javascript: matrix: 10 days
javascript: bob: 16 days
javascript: pascals-triangle: 11 days
javascript: linked-list: 7 months
javascript: grade-school: 11 days
javascript: list-ops: 11 days
javascript: robot-name: None mentored
javascript: simple-cipher: 20 days
javascript: wordy: 15 days
javascript: secret-handshake: None mentored

julia: leap: 2 days
julia: nucleotide-count: 11 days
julia: pangram: 27 days
julia: rotational-cipher: None mentored
julia: difference-of-squares: None mentored
julia: raindrops: None mentored
julia: secret-handshake: None mentored
julia: clock: None mentored
julia: robot-name: None mentored

kotlin: two-fer: about 1 hour
kotlin: hamming: 17 days
kotlin: gigasecond: 6 days
kotlin: scrabble-score: 5 days
kotlin: difference-of-squares: None mentored
kotlin: secret-handshake: about 1 month
kotlin: triangle: None mentored
kotlin: saddle-points: None mentored
kotlin: flatten-array: 6 months
kotlin: word-count: None mentored
kotlin: robot-name: None mentored
kotlin: rotational-cipher: 20 days
kotlin: bank-account: None mentored
kotlin: linked-list: None mentored
kotlin: binary-search: None mentored

lua: hamming: 8 days
lua: house: 2 days
lua: difference-of-squares: 1 day
lua: binary-search: None mentored
lua: matrix: None mentored
lua: isogram: None mentored
lua: bank-account: None mentored
lua: nth-prime: None mentored
lua: diamond: None mentored
lua: run-length-encoding: None mentored
lua: robot-name: None mentored
lua: leap: None mentored
lua: custom-set: None mentored
lua: pig-latin: None mentored
lua: list-ops: None mentored
lua: binary: None mentored
lua: allergies: None mentored

mips: binary: None mentored
mips: leap: None mentored
mips: difference-of-squares: None mentored
mips: hamming: None mentored
mips: triangle: None mentored
mips: atbash-cipher: None mentored
mips: scrabble-score: None mentored
mips: raindrops: None mentored
mips: nth-prime: None mentored

nim: two-fer: 4 days
nim: leap: 3 days
nim: bob: 2 days
nim: allergies: None mentored
nim: sum-of-multiples: 11 days
nim: grade-school: 11 days

objective-c: two-fer: None mentored
objective-c: bob: None mentored
objective-c: leap: None mentored
objective-c: gigasecond: None mentored
objective-c: difference-of-squares: None mentored
objective-c: reverse-string: None mentored
objective-c: sum-of-multiples: None mentored
objective-c: space-age: None mentored
objective-c: hamming: None mentored
objective-c: nucleotide-count: None mentored

ocaml: leap: 13 days
ocaml: hamming: None mentored
ocaml: raindrops: about 1 month
ocaml: difference-of-squares: about 1 month
ocaml: rna-transcription: None mentored
ocaml: nucleotide-count: None mentored
ocaml: etl: None mentored
ocaml: grade-school: None mentored
ocaml: bob: None mentored
ocaml: allergies: None mentored

perl5: two-fer: about 19 hours
perl5: bob: 1 day
perl5: leap: about 7 hours
perl5: grains: 1 day
perl5: raindrops: about 10 hours
perl5: hamming: about 6 hours
perl5: etl: None mentored
perl5: scrabble-score: about 9 hours
perl5: word-count: None mentored
perl5: anagram: None mentored

perl6: leap: None mentored
perl6: bob: None mentored
perl6: nucleotide-count: None mentored
perl6: pangram: None mentored
perl6: clock: None mentored
perl6: raindrops: None mentored
perl6: phone-number: None mentored
perl6: allergies: None mentored
perl6: all-your-base: None mentored
perl6: robot-name: None mentored

pharo-smalltalk: two-fer: about 14 hours
pharo-smalltalk: leap: 1 day
pharo-smalltalk: reverse-string: 1 day
pharo-smalltalk: isogram: about 15 hours
pharo-smalltalk: grains: 3 days
pharo-smalltalk: allergies: 7 days
pharo-smalltalk: matrix: None mentored
pharo-smalltalk: grade-school: None mentored
pharo-smalltalk: forth: None mentored

php: hamming: about 23 hours
php: gigasecond: about 12 hours
php: bob: 1 day
php: rna-transcription: 4 days
php: luhn: 1 day
php: isogram: 5 days
php: robot-name: 3 days
php: difference-of-squares: 7 days
php: grade-school: 1 day
php: robot-simulator: about 14 hours
php: run-length-encoding: 4 days
php: largest-series-product: 4 days

plsql: hamming: None mentored
plsql: gigasecond: None mentored
plsql: rna-transcription: None mentored
plsql: raindrops: None mentored
plsql: difference-of-squares: None mentored
plsql: roman-numerals: None mentored
plsql: nth-prime: None mentored
plsql: leap: None mentored
plsql: grains: None mentored
plsql: binary: None mentored

pony: difference-of-squares: None mentored
pony: bob: None mentored
pony: hamming: None mentored
pony: leap: None mentored
pony: anagram: None mentored
pony: rna-transcription: None mentored
pony: roman-numerals: None mentored
pony: beer-song: None mentored
pony: atbash-cipher: None mentored
pony: pascals-triangle: None mentored

powershell: bob: None mentored
powershell: sum-of-multiples: None mentored
powershell: raindrops: None mentored
powershell: nucleotide-count: None mentored

prolog: queen-attack: None mentored
prolog: triangle: None mentored
prolog: isogram: None mentored
prolog: binary: None mentored
prolog: rna-transcription: None mentored
prolog: anagram: None mentored
prolog: pascals-triangle: None mentored
prolog: dominoes: None mentored

purescript: leap: None mentored
purescript: bob: None mentored
purescript: raindrops: None mentored
purescript: hamming: None mentored
purescript: pangram: None mentored
purescript: scrabble-score: None mentored
purescript: accumulate: None mentored
purescript: acronym: None mentored
purescript: triangle: None mentored
purescript: word-count: None mentored

python: two-fer: 5 days
python: high-scores: about 9 hours
python: matrix: 16 days
python: hamming: 25 days
python: raindrops: 29 days
python: isogram: 23 days
python: twelve-days: about 1 month
python: word-count: about 2 months
python: scrabble-score: about 1 month
python: acronym: 28 days
python: kindergarten-garden: about 1 month
python: grade-school: about 1 month
python: luhn: 28 days
python: clock: 21 days
python: markdown: about 2 months
python: tournament: about 2 months
python: book-store: 30 days

r: two-fer: 1 day
r: leap: 1 day
r: hamming: 3 days
r: raindrops: 1 day
r: bob: 2 days
r: anagram: 4 days
r: sum-of-multiples: 3 days
r: word-count: None mentored
r: phone-number: 2 days
r: rotational-cipher: 3 days
r: largest-series-product: 20 days
r: pascals-triangle: 4 days

racket: grains: 5 days
racket: two-fer: 4 days
racket: leap: 7 days
racket: difference-of-squares: 3 days
racket: perfect-numbers: 10 days
racket: gigasecond: 10 days
racket: bob: 4 days
racket: collatz-conjecture: 11 days
racket: hamming: None mentored
racket: scrabble-score: None mentored

reasonml: leap: None mentored
reasonml: bob: None mentored
reasonml: rna-transcription: None mentored
reasonml: word-count: None mentored
reasonml: phone-number: None mentored
reasonml: binary-search: None mentored
reasonml: run-length-encoding: None mentored

ruby: two-fer: about 10 hours
ruby: acronym: about 14 hours
ruby: high-scores: 1 day
ruby: matrix: about 18 hours
ruby: series: 3 days
ruby: word-count: about 13 hours
ruby: hamming: about 20 hours
ruby: raindrops: about 7 hours
ruby: isogram: 3 days
ruby: scrabble-score: about 22 hours
ruby: luhn: 1 day
ruby: clock: 6 days
ruby: twelve-days: 2 days
ruby: tournament: 6 days

rust: reverse-string: 6 days
rust: gigasecond: 4 days
rust: bob: 24 days
rust: clock: 14 days
rust: atbash-cipher: 13 days
rust: anagram: about 1 month
rust: space-age: None mentored
rust: sublist: None mentored
rust: minesweeper: None mentored
rust: luhn: None mentored
rust: parallel-letter-frequency: None mentored
rust: macros: None mentored
rust: poker: None mentored
rust: forth: None mentored

scala: two-fer: about 2 hours
scala: leap: about 10 hours
scala: bob: 2 days
scala: space-age: about 7 hours
scala: sum-of-multiples: about 22 hours
scala: grade-school: 1 day
scala: accumulate: about 8 hours
scala: hamming: about 5 hours
scala: etl: about 16 hours
scala: perfect-numbers: 4 days
scala: secret-handshake: about 16 hours
scala: robot-simulator: None mentored
scala: matrix: about 5 hours

scheme: hamming: None mentored
scheme: leap: None mentored
scheme: grains: None mentored
scheme: bob: None mentored
scheme: raindrops: None mentored
scheme: rna-transcription: None mentored
scheme: robot-name: None mentored
scheme: phone-number: None mentored
scheme: anagram: None mentored
scheme: nucleotide-count: None mentored

sml: two-fer: 2 days
sml: leap: about 14 hours

swift: two-fer: 2 days
swift: leap: 7 days
swift: gigasecond: 6 days
swift: difference-of-squares: 6 days
swift: rna-transcription: 8 days
swift: sum-of-multiples: 6 days
swift: space-age: 6 days
swift: bob: 4 days
swift: grains: 7 days
swift: hamming: 4 days

typescript: two-fer: 14 days
typescript: leap: 6 days
typescript: rna-transcription: None mentored
typescript: space-age: None mentored
typescript: pangram: 6 months
typescript: bob: 3 months
typescript: matrix: None mentored
typescript: robot-name: None mentored
typescript: grade-school: None mentored
typescript: clock: None mentored
typescript: secret-handshake: None mentored
typescript: binary-search: None mentored
typescript: linked-list: None mentored
typescript: rational-numbers: None mentored
typescript: atbash-cipher: None mentored
typescript: simple-cipher: 6 months
typescript: wordy: None mentored
typescript: list-ops: None mentored

vbnet: bob: None mentored
vbnet: anagram: None mentored
vbnet: binary: None mentored
vbnet: allergies: None mentored
vbnet: atbash-cipher: None mentored
vbnet: accumulate: None mentored
vbnet: crypto-square: None mentored

vimscript: leap: None mentored
vimscript: hamming: None mentored
vimscript: raindrops: None mentored
vimscript: scrabble-score: None mentored
vimscript: word-count: about 1 month