need help with this PS question....

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nina11: Newbie | Next Rank: 10 Posts; Posts: 8; Joined: Thu Aug 04, 2011 12:06 am

need help with this PS question....

by nina11 » Fri Jan 20, 2012 3:57 am

hi guys,

i am stumped over this problem and i really need help with this.

the number 75 can be written as the sum of squares of 3 different positive integers. what is the sum of these integers?

A. 17
B. 16
C. 15
D. 14
E. 13

really appreciate any help for this. also if you get the answer can you tell me a shortcut method also??i just tried a trial and error and even if i find any answer to a similar problem, it takes soo much time!!!...

thanks

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Source: Beat The GMAT — Quantitative Reasoning | Fri Jan 20, 2012 3:57 am

sam2304: Legendary Member; Posts: 1239; Joined: Tue Apr 26, 2011 6:25 am; Thanked: 233 times; Followed by:26 members; GMAT Score:680

by sam2304 » Fri Jan 20, 2012 5:15 am

I don't think it was that time consuming. These are the nos

1 4 9 16 25 36 49 64

As soon as you see the list you know the answer.

IMO E.

Getting defeated is just a temporary notion, giving it up is what makes it permanent.
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GMAT/MBA Expert

Brent@GMATPrepNow: 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 » Fri Jan 20, 2012 6:15 am

sam2304 wrote:I don't think it was that time consuming. These are the nos

1 4 9 16 25 36 49 64

As soon as you see the list you know the answer.

IMO E.

Nice approach, sam2304

In case anyone doesn't see the required values, they are [spoiler]1 + 25 + 49 = 75[/spoiler]
In other words [spoiler]1^2 + 5^2 + 7^2 = 75 (1+5+7=13=E)[/spoiler]

Cheers,
Brent

Brent Hanneson - Creator of GMATPrepNow.com