The average (arithmetic mean) of integers \(r, s, t, u\),

This topic has expert replies
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3008
Joined: Mon Aug 22, 2016 6:19 am
Location: Grand Central / New York
Thanked: 470 times
Followed by:34 members

by Jay@ManhattanReview » Wed Dec 04, 2019 12:27 am
M7MBA wrote:The average (arithmetic mean) of integers \(r, s, t, u\), and \(v\) is 100. Are exactly two of the integers greater than 100?

(1) Three of the integers are less than 50.
(2) None of the integers is equal to 100.

[spoiler]OA=E[/spoiler]

Source: Princeton Review
Given that the average (arithmetic mean) of integers \(r, s, t, u\), and \(v\) is 100, we have r + s + t + u + v = 500.

Let's take each statement one by one.

(1) Three of the integers are less than 50.

Say r = s = t = 49, thus, from r + s + t + u + v = 500, we have u + v = 353.

Case 1: Say u = 53, then v = 300 > 100. The answer is no.
Case 2: Say u = 153, then v = 200 > 100. The answer is yes.

No unique answer. Insufficient.

(2) None of the integers is equal to 100.

Certainly insufficient.

(1) and (2) together

Both cases discussed above are applicable here. Insufficient.

The correct answer: E

Hope this helps!

-Jay
_________________
Manhattan Review GRE Prep

Locations: GRE Classes Raleigh NC | GRE Prep Course Singapore | GRE Prep Philadelphia | SAT Prep Classes Toronto | and many more...

Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.