Update simple-interest.sh

Corrected the calculation of simple interest

Author: Surbhi-0204

simple-interest.sh

@@ -21,6 +21,6 @@ read r
 echo "Enter time period in years:"
 read t
 
-s=$(expr $p \* $t \* $r / 100)
+s=$(expr ($p * $t * $r )/ 100)
 echo "The simple interest is: "
 echo $s