Sum of positive integers x and y is 72

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

Redeem

This topic has expert replies

Post new topic Post Reply

Previous Topic Next Topic

rd85: Senior | Next Rank: 100 Posts; Posts: 39; Joined: Mon May 19, 2008 4:43 am

Sum of positive integers x and y is 72

by rd85 » Thu Jul 16, 2009 2:29 am

Sum of positive integers x and y is 72. What is xy?
a. x = y + 1
b. x and y have same tens digit

OA is D, whereas I feel it should be A.

Consider II statement,
(X,Y) / (Y,X) can be (33,39) (34,38) (35,37) (36,36)

So how can we deduce a definite answer? We have 4 different values of X and Y. Please correct me if I am wrong.

Quote

Source: Beat The GMAT — Data Sufficiency | Thu Jul 16, 2009 2:29 am

nitya34: Master | Next Rank: 500 Posts; Posts: 179; Joined: Tue Jan 08, 2008 7:23 pm; Thanked: 11 times; GMAT Score:590

by nitya34 » Thu Jul 16, 2009 2:57 am

Whats the Source?

How on earth it is D?
be coz if we use (1), we get y=71/2=Non Integer

hence IMO E

Many of the great achievements of the world were accomplished by tired and discouraged men who kept on working.

Quote

rd85: Senior | Next Rank: 100 Posts; Posts: 39; Joined: Mon May 19, 2008 4:43 am

by rd85 » Thu Jul 16, 2009 5:01 am

I am not sure how the answer is D. Anyway, I realised that I was reading the question incorrectly. The answer should be E.

Source is

https://www.beatthegmat.com/answers-to-9 ... 35974.html

Quote

niraj_a: Legendary Member; Posts: 708; Joined: Sun Jun 01, 2008 4:59 am; Location: USA; Thanked: 13 times; Followed by:1 members

by niraj_a » Thu Jul 16, 2009 6:17 am

i think i'm a little slow this morning.

why is statement 2 not sufficient? 36 + 36 = 72. i couldn't find other combinations with the same tens digit i.e. 3 in my example above.

Quote

Morgoth: Master | Next Rank: 500 Posts; Posts: 316; Joined: Mon Sep 22, 2008 12:04 am; Thanked: 36 times; Followed by:1 members

Re: Sum of positive integers x and y is 72

by Morgoth » Thu Jul 16, 2009 10:36 am

rajbirdadhiyala wrote:Sum of positive integers x and y is 72. What is xy?
a. x = y + 1
b. x and y have same tens digit

OA is D, whereas I feel it should be A.

Consider II statement,
(X,Y) / (Y,X) can be (33,39) (34,38) (35,37) (36,36)

So how can we deduce a definite answer? We have 4 different values of X and Y. Please correct me if I am wrong.

There is no way this question could be correct.

question says x and y are positive integers, however if you look ta statement I, you will realize that x and y are both consecutive integers, this means

if x is odd, then y will be even

if y is odd, then x will be even

Odd + even = odd

therefore, no way on earth x+y = 72. This simply shows that either the question is wrong or something is missing in the statements.

If look ta statement II, we know that both x and y are 2 digit integers, whose tens digit is same.

34+38, 33+39

Insufficient.

Quote

real2008: Legendary Member; Posts: 527; Joined: Thu May 01, 2008 12:06 am; Thanked: 7 times

Re: Sum of positive integers x and y is 72

by real2008 » Fri Jul 17, 2009 12:56 pm

rajbirdadhiyala wrote:Sum of positive integers x and y is 72. What is xy?
a. x = y + 1
b. x and y have same tens digit

OA is D, whereas I feel it should be A.

Consider II statement,
(X,Y) / (Y,X) can be (33,39) (34,38) (35,37) (36,36)

So how can we deduce a definite answer? We have 4 different values of X and Y. Please correct me if I am wrong.

probably the qn may be :

Product of positive integers x and y is 72. What is x+y?
a. x = y + 1
b. x and y have same tens digit

then try.

Quote

Morgoth: Master | Next Rank: 500 Posts; Posts: 316; Joined: Mon Sep 22, 2008 12:04 am; Thanked: 36 times; Followed by:1 members

Re: Sum of positive integers x and y is 72

by Morgoth » Sat Jul 18, 2009 5:13 am

real2008 wrote:
probably the qn may be :

Product of positive integers x and y is 72. What is x+y?
a. x = y + 1
b. x and y have same tens digit

then try.

If you consider this question.

The statement I will be sufficient.

Positive integers, x=y+1, consecutive integers. xy=72

only option is 8*9

Sufficient.

Statement II

this will be a default meaning case does not exist. 72 = 8*9, 12*6, 72*1, etc. but none of the two digits will ever have same tens digit. Hence, this contradicts the statement.