Question 79 Problem Solving 2020 GMAT Quantitative Review

Question 79 Problem Solving 2020 GMAT Quantitative Review

Video explanation [PQID: PS87502.01]: If Car A took n hours to travel 2 miles and Car B…

Comments

Nicosays

Hello, I thought you can’t add rates together? Or is that for a separate type of problem where you have to find the total distance of the trip versus the total time to find the average speed?

You are right that in general you can’t add rates, but in this particular problem they are telling us about a situation where Car C is to travel at a rate that is the average of Car A and Car B. This is a made up condition, and all I am doing is applying the average to find the rate of Car C.

The thing about GMAT problems is that you have to interpret the specific question and apply the given condition. You don’t always get a problem that follows a set pattern.

Nico says

Hello, I thought you can’t add rates together? Or is that for a separate type of problem where you have to find the total distance of the trip versus the total time to find the average speed?

GMAT Quantum says

Hi Nico,

You are right that in general you can’t add rates, but in this particular problem they are telling us about a situation where Car C is to travel at a rate that is the average of Car A and Car B. This is a made up condition, and all I am doing is applying the average to find the rate of Car C.

The thing about GMAT problems is that you have to interpret the specific question and apply the given condition. You don’t always get a problem that follows a set pattern.

I hope this makes sense.

Dabral