Shell Programming and Scripting

line 17: [: expr: integer expression expected 1

 #!/bin/sh
  2 ## Name of the program is test_script_b.sh
  3 
  4 ##request information from the user
  5 echo enter 3 numbers
  6 read a b c
  7 
  8 ##check for proper range of numbers
  9 if [ $a -gt 10 -o $b -gt 10 -o $c -gt 5 ]; then
 10 echo "numbers out of range"
 11 exit 1
 12 fi
 13 
 14 ## process data
 15 x=($a + $b + $c)
 16 
 17 while [ $x -gt 0 ]
 18 do
 19         echo "(($x / 2 % 2))"
 20         x=(expr $x - 1)
 21 done
 22 
 23 ## end of program

14 ## process data
15 x=$((a + b + c))
16 
17 while [ $x -gt 0 ]
18 do
19   echo "$((x / 2 % 2))"
20   x=$(( x - 1))
21 done

set -x
read a b c
x=($a + $b + $c)
echo "$x"
x=$((a + b + c))
echo "$x"

+ read a b c
2 7 21
+ x=($a + $b + $c)
+ echo 2
2
+ x=30
+ echo 30
30