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 Author: questioner [ Tue Nov 02, 2010 3:22 am ] Post subject: GMAT Fractions A very similar question is http://800score.com/forum/viewtopic.php?t=128.Which of the following fractions is the largest?A. 11/14B. 4/5C. 9/14D. 7/10E. 5/6(E) One way to solve this type of problem is to find the lowest common denominator for all of the fractions.To do this, first factor all of the denominators:11/14: 14 factors into 2 and 74/5: 5 is prime17/21: 21 factors into 3 and 729/35: 35 factors into 5 and 75/6: 6 factors into 2 and 3.Then, to get a common denominator, we make sure that each of the factors is represented exactly once (since no factor is raised to a power in any denominator):2 × 3 × 5 × 7 = 210.Therefore, 210 is the lowest common denominator. Now we can express all the fractions in terms of the common denominator of 210 to see which is the largest:11/14 × 15/15 = 165/2104/5 × 42/42 = 168/2109/14 × 15/15 = 135/2107/10 × 21/21 = 147/2105/6 × 35/35 = 175/210.Therefore, 5/6 is the largest (175/210). The correct answer is choice (E).-------------I don't understand how you arrived at 15/15 , 42/42, 15/15 , 21/21, 35/35.Can you please explain further.

 Author: Gennadiy [ Tue Nov 02, 2010 3:29 am ] Post subject: Re: math (test 1, question 13): fractions Once we find that the common denominator is 210, we need to convert all the fractions. Let us convert the fraction 11/14 first.210 / 14 = 15. Therefore wee need to multiple the denominator by 15 to get 210. In order to keep the fraction the same we need to multiply the numerator by 15 as well.11/14 = (11 × 15)/(14 × 15) = 165/210.The rest of the fractions are converted the same way.

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