BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

sum of the squares?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 72
Joined: Sun Nov 03, 2013 9:29 am
Thanked: 1 times

sum of the squares?

by josh80 » Wed Dec 11, 2013 5:01 pm
The number 75 can be written as the sum of the squares of 3 different positive integers. What is the sum of these 3 integers?

- 17
- 16
- 15
- 14
- 13
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Wed Dec 11, 2013 5:13 pm
josh80 wrote:The number 75 can be written as the sum of the squares of 3 different positive integers. What is the sum of these 3 integers?

A) 17
B) 16
C) 15
D) 14
E) 13
We're looking for 3 DIFFERENT squares that add to 75

Here are the only squares we need to consider: 1, 4, 9, 16, 25, 36, 49, 64
Can you find 3 that add to 75?
After some fiddling, we may notice that 1 + 25 + 49
In other words, 1² + 5² + 7² = 75
We want the SUM of 1 + 5 + 7, which is 13

Answer: E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1