#!/bin/bash

echo -n "Enter assignment mark:"
read assign

echo -n "Enter Test 1 mark:"
read test1

echo -n "Enter Test 2 mark:"
read test2

echo -n "Enter Final Exam mark:"
read final

total=$(($assign + $test1 + $test2 + $final))

if [[ $total -ge 90  &&  $total -le 100 ]]; then
echo "Your grade is A+"

elif [[ $total -ge 85  &&  $total -le 89 ]]; then
echo "Your grade is A"

elif [[ $total -ge 80  &&  $total -le 84 ]]; then
echo "Your grade is A-";

elif [[ $total -ge 77  &&  $total -le 79 ]]; then
echo "Your grade is B+"

elif [[ $total -ge 73  &&  $total -le 76 ]]; then
echo "Your grade is B"

elif [[ $total -ge 70  &&  $total -le 72 ]]; then
echo "Your grade is B-"

elif [[ $total -ge 67  &&  $total -le 69 ]]; then
echo "Your grade is C+"

elif [[ $total -ge 63  &&  $total -le 66 ]]; then
echo "Your grade is C"

elif [[ $total -ge 60  &&  $total -le 62 ]]; then
echo "Your grade is C-"

elif [[ $total -ge 57  &&  $total -le 59 ]]; then
echo "Your grade is D+"

elif [[ $total -ge 53  &&  $total -le 56 ]]; then
echo "Your grade is D"

elif [[ $total -ge 50  &&  $total -le 52 ]]; then
echo "Your grade is D-"

elif [[ $total -ge 0  &&  $total -le 49 ]]; then
echo "Your grade is F"

else
echo "?"
fi