SUM?

[grandh01]

A certain fraction is equivalent to
2/5. If the numerator of the fraction is
increased by 4 and the denominator is
doubled, the new fraction is
equivalent to
1/3. What is the sum of
the numerator and denominator of the
original fraction?
(A) 49 (B) 35 (C) 28
(D) 26 (E) 21

OA is E

[truplayer256]

Let x/y = 2/5.

(x + 4)/(2y) = 1/3 => 1/2(x/y) + 2/y = 1/3

1/5 + 2/y = 1/3 => 2/y = 2/15

y = 15

x = (2/5)(15) = 6

x + y = 21

Choose E.

[Anurag@Gurome]

A certain fraction is equivalent to
2/5. If the numerator of the fraction is
increased by 4 and the denominator is
doubled, the new fraction is
equivalent to
1/3. What is the sum of
the numerator and denominator of the
original fraction?
(A) 49 (B) 35 (C) 28
(D) 26 (E) 21

OA is E

Let us assume that the fraction is 2x/5x.
Then (2x + 4)/(10x) = 1/3
6x + 12 = 10x
4x = 12
x = 3
Original fraction = (2 * 3)/(5 * 3) = 6/15
Sum of numerator and denominator = 6 + 15 = 21

The correct answer is E.