Show Answer - Magoosh GMAT

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Choose the correct statement.

A certain aquarium holds three types of fish: angelfish, swordtails and guppies. What is the ratio of the number of guppies to the number of angelfish?

(1) There are 200 fish in the aquarium

(2) 45 percent of the fish are swordtails, and there are twice as many swordtails as there are angelfish.

Statement 1 ALONE is sufficient to answer the question, but statement 2 alone is NOT sufficient. Statement 2 ALONE is sufficient to answer the question, but statement 1 alone is NOT sufficient. BOTH statements 1 and 2 TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient. Each statement ALONE is sufficient to answer the question. Statement 1 and 2 TOGETHER are NOT sufficient to answer the question.

Title

Guppies, angelfish and swordtails

Your Result

Correct

Difficulty

Medium

Your Pace

0:02

Others' Pace

1:24

Video Explanation

Text Explanation

Statement 1 doesn't tell us anything about the ratio of fish, so it is insufficient. Statement 2 tells us that 45% are swordtails and that there are twice as many swordtails as angelfish. That means that 22.5% are angelfish (half of 45%). Now we have 45% and 22.5%, and there's only one other kind of fish: guppies. Percents add up to 100%, so 32.5% are guppies. That means that the ratio of the number of guppies to the number of angelfish is 32.5:22.5, and statement 2 is sufficient. The answer is (B).

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