Problem: Let r​ and s​ be positive numbers with r​ greater than s​. Let R=r+1 and S=s+1. The difference in percent by which r exceeds s​ and R​ exceeds S​ is:
Answer Choices:
A. r100(r−s)​
B. s100(r−s)​
C. r+1100(r−s)​
D. s+1100(r−s)​
E. none of these
Solution:
(sr−s​−s+1(r+1)−(s+1)​)100=s(s+1)100(r−s)​