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Source: — Problem Solving |

by Jim@StratusPrep » Tue Jan 24, 2012 11:39 pm
I think you have these back words... LCM = 84 and HCF = 21

If the highest common factor is 21 then they both share a 7 and a 3 as factors

If the Lowest common multiple is 84 then between the two of them they must have the factors of 7 * 3 * 2 * 2

Since the smallest cannot have a 2 (otherwise the HCF would be 42), 84 must be the largest number, which is 4 * 21
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by Anurag@Gurome » Tue Jan 24, 2012 11:41 pm
venki_88 wrote:HCF and LCM of two numbers are 84 and 21.If ratio of two numbers is 1:4.Then largest of two numbers is
Product of the two numbers = HCF*LCM = 84*21

Say, the numbers are x and 4x.
Hence, product of the numbers = 4x² = 84*21 = 4*21*21

Hence, x = 21 --> 4x = 4*21

The correct answer is B.
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by ArunangsuSahu » Wed Jan 25, 2012 11:56 am
4*21
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