If P=S(1+r/100)^n where P is the amount from investment, S i

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If P=S(1+r/100)^n where P is the amount from investment, S is principal, and r is a compound interest rate after n years, by what percent the amount from investment increases between after n years and after n+5 years?

1) n=10
2) r=10


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Source: — Data Sufficiency |

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by Max@Math Revolution » Sun Apr 03, 2016 1:51 am
Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

If P=S(1+r/100)^n where P is the amount from investment, S is principal, and r is a compound interest rate after n years, by what percent the amount from investment increases between after n years and after n+5 years?

1) n=10
2) r=10


When you modify the original condition and the question, you only need to figure out r from
Image

Thus, B is the answer.