Find the numbers which are in the ratio 3 : 2 : 4 such that the sum of the first and the second added to the difference of the third and the second is 21 ?  Choose the correct choice from the following answers:
A) 3,3,3  B) 4,4,3  C) 4,5,3  D) 9, 6, 12  E) 2,4,4
Let the numbers be a, b and c.   Given that a, b and c are in the ratio 3 : 2 : 4.   let, a = 3x, b = 2x and c = 4x   Given, (a+b) + (c - b) = 21   = &gt; a + b + c - b = 21 = &gt; a + c = 21   = &gt; 3x + 4x = 21 = &gt;7x = 21 = &gt; x = 3   a , b , c are 3x, 2x, 4x.   a, b, c are 9 , 6 , 12.   Answer:9, 6, 12
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Find the numbers which are in the ratio 3 : 2 : 4 such that the sum of the first and the second added to the difference of the third and the second is 21 ?