Gmat_mission wrote:If a certain animated cartoon consists of a total of 17,280 frames on film, how many minutes will it take to run the cartoon?

(1) The cartoon runs without interruption at the rate of 24 frames per second.
(2) It takes 6 times as long to run the cartoon as it takes to rewind the film, and it takes a total of 14 minutes to do both.

[spoiler]OA=D[/spoiler]

Source: Official Guide

Target question: How many minutes will it take to run the cartoon?

Given: cartoon consists of a total of 17,280 frames

Statement 1: The cartoon runs without interruption at the rate of 24 frames per second.
Time = (output)/(rate)
So, time = (17,280 frames)/(24 frames per second)
NOTE: we're not going to evaluate this. We need only recognize that we COULD evaluate it and, thus, determine the time.
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: It takes 6 times as long to run the carton as it takes to rewind the film, and it takes a total of 14 minutes to do both.
We don't even need to apply any rate-time formulas here.
Instead, we'll use some algebra.

Let t = # of minutes to rewind film.
So, 6t = # of minutes to play film
So, t + 6t = 14
Simplify: 7t = 14
Solve: t = 2
So, it takes 2 minutes to rewind the film, which means it takes 12 minutes to play the film
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: D

Cheers,
Brent