Write a program that calculates the total grade for N classroom
exerciss as a percentage. The user should input the value for N
folowed by each of the N scores and totals. Calculate the overall
percentage (sum of the total points earned divided by the total points
possible) and output it as a percentage. Sample input and output is
shown below.

How many exercises to input?  3

Score received for exercise 1: 10
Total points possible for exercise 1: 10

Score received for exercise 2: 7
Total points possible for exercise 2: 12

Score received for exercise 3: 5
Total points possible for exercise 3: 8

Your total is 22 out of 30, or 73.33%.