Problem Solving

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

A certain fraction is equivalent to 2/5, i.e. 2x/5x, where x is any integer.
The question states that numerator is increased by 4 & denominator is doubled, i.e (2x+4)/(2*5x) = 1/3 ==> (2x+4)/10x = 1/3. Solving for x, we get x = 3. Substitute x in the orginial fraction & add the numerator value with denominator value, i.e. 2*3+5*3=21.

E is the answer. Hope this helps.

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Vemuri wrote:A certain fraction is equivalent to 2/5, i.e. 2x/5x, where x is any integer.
The question states that numerator is increased by 4 & denominator is doubled, i.e (2x+4)/(2*5x) = 1/3 ==> (2x+4)/10x = 1/3. Solving for x, we get x = 3. Substitute x in the orginial fraction & add the numerator value with denominator value, i.e. 2*3+5*3=21.

D is the answer. Hope this helps.

-------------------------------------------------
Earth Hour 2009
Vote Earth! Your light switch is your vote.
https://www.earthhour.org/home/

21 is (E) =P....

shibal wrote: 21 is (E) =P....

Thanks for correcting Shibal