Bunuel wrote:

The percent change from 50 to 52 is NOT equivalent to the percent change from

A. 500 to 520

B. 200 to 208

C. 100 to 104

D. 25 to 26

E. 10 to 12

30-second way, no long division, no calculating percent change: Use a multiplier or compare fractions. These answers' numbers are easy.

This question is about equivalent

ratios, too. For percent change to be equivalent, the ratio of (A:B) in the answers must be identical to ratio of 50:52.

Choose the easiest: multipliers, divisors, or fraction comparison (\(\frac{50}{52}\) compared to \(\frac{A}{B}\))

A) 500 to 520:

50 *

10 = 500

52 *

10 = 520

Same multiplier. Ratio holds. Equivalent percent change. EQUIVALENT

B. 200 to 208:

50 *

4 = 200. 52 * 4? 208. EQUIVALENT

C. 100 to 104

50 *

2 = 100. 52 * 2? 104. EQUIVALENT

D. 25 to 26

\(\frac{50}{2}\) = 25. \(\frac{52}{2}\)? 26. EQUIVALENT

E. 10 to 12:

By POE this is the answer.

10 *

5 = 50. 12 * 5?

12 * 5 = 60, and \(60\neq{52}\).

Ratios are not equivalent. Hence percent change is NOT EQUIVALENT.*

ANSWER E

*

If in doubt, do the math for just this answer.

Percent change from 50 to 52?

\(\frac{52-50}{50} = \frac{2}{50}\) = .04 * 100 = 4%

Percent change from 10 to 12?

\(\frac{2}{10}\) = .20 * 100 = 20%
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