number properties

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by Anurag@Gurome » Wed Jan 25, 2012 8:35 pm
sud21 wrote:If 140*n is the square of an integer, where n is an integer. What is the least value of n?
140*n = (2^2)*5*7*n

Now if 140*n is a square of an integer, then all the factors of 140*n must appear in it even number of times. There are two 2's already in 140*n. Hence, n must contain 5 and 7 in it.

Hence, minimum possible value of n = 5*7 = 35
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by ArunangsuSahu » Wed Jan 25, 2012 9:29 pm