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by ronnie1985 » Tue May 22, 2012 11:30 am
How many positive integers less than 10,000 are there in which sum of digits equals 5?
(a) 31
(b) 51
(c) 56
(d) 62
(e) 93

I got 56 by a long method after recognizing the pattern, then answer is right, but I took 10 minutes to solve.

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by Brent@GMATPrepNow » Tue May 22, 2012 11:58 am
ronnie1985 wrote:How many positive integers less than 10,000 are there in which sum of digits equals 5?
(a) 31
(b) 51
(c) 56
(d) 62
(e) 93

I got 56 by a long method after recognizing the pattern, then answer is right, but I took 10 minutes to solve.

Please help...
This is often referred to as a partition question.
Here's my solution:

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Brent

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by Brent@GMATPrepNow » Tue May 22, 2012 12:00 pm
By the way, here's a longer discussion on the question: https://www.beatthegmat.com/very-tricky- ... 25349.html

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