Gmat_mission wrote: ↑

Thu Jan 07, 2021 10:57 am

In a recent town election, what was the ratio of the number of votes in favor of a certain proposal to the number of votes against the proposal?

(1) There were 60 more votes in favor of the proposal than against the proposal.
(2) There were 240 votes in favor of the proposal.

Answer: C

Source: Official Guide

Let F = the number of votes in FAVOR of the proposal
Let A = the number of votes AGAINST the proposal

Target question: What is the value of F/A?

Statement 1: There were 60 more votes in favor of the proposal than against the proposal.
In other words, F = A + 60
Let's TEST some values.
There are several values of F and A that satisfy the equation F = A + 60. Here are two:
Case a: F = 70 and A = 10. In this case, the answer to the target question is F/A = 70/10
Case b: F = 80 and A = 20. In this case, the answer to the target question is F/A = 80/20
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: There were 240 votes in favor of the proposal.
In other words, F = 240
Since we have no information about the number of votes AGAINST the proposal (i.e., the value of A), we cannot answer the target question.
So, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 1 tells us that F = A + 60
Statement 2 tells us that F = 240
When we use BOTH statements, we can conclude that A = 180 (and F = 240)
So, the answer to the target question is F/A = 240/180
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer: C

Cheers,
Brent