1.

2.

BEGIN { FS="[ :,]"
max = -1
i = 0 }{
while(getline == 1){
sum = $2 + $3
  if(sum == max){
   b=$1 $3 ":" $2
   tab[i] = b
   i = i+ 1
  }
  else if(sum > max ){
   max = sum
   b=$1 $2 ":" $3
   i = 0
   split("", tab)
   tab[i] = b
   i = i + 1
 }
}
for( x in tab){
   print tab[x]
}}
3.

BEGIN { FS="[,]"
sum = 0
}
{
while(getline == 1){
 sum = sum + $2
}
 print sum
}

4.

BEGIN { FS="[,]"
max = 0
count = 0
sum = 0
}{
if(count == 4){
    print max
    count = 0
}
if(count < 4){
    if( max < $2  ){
        max = $2
        details = $1 ", " $2
    }
count = count + 1
}
}

5.

6.