# function_1 extract lines with word Mark from file.
function_1() {
    file=$1
    grep "Mark" ${file}
}
Suppose output of funtion_1:
- Question 1: Mark :5:
- Question 2: Mark :1:
- Question 3: Mark :3:
Suppose function_2 needs to extract integer from function_1 output to calculate total mark. 
How to give output of function_1 to funtion_2?
 
     
     
    