Question

If decreasing 70 by X percent results in the same number as increasing 60 by X percent ,than what is X percent?

Answer 1

Turn the sentences into a formula:  

Notes:

1. Decreasing 70 by X% expresses to: 70 - X %,

2. Increasing 60 by X% expresses to: 60 + X%,

3. Results the same number implies eq.(1) = eq.(2)

So the formula is:  

70 – X% = 60 + X% (Separate X% and numbers on LHS and RHS, respectively)

2X% = 10

X % = 10/2  

X % = 5%

5% is the correct answer.

To prove:

70-5 = 60 + 5 (After placing the answer in X%)

65 = 65