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 1/4. What is the difference of the numerator and denominator of the original fraction?
Choose the correct choice from the following
A) 49
B) 35
C) 28
D) 24
E) 21
x/y = 2/5 -&gt; 1   (x+4)/2y = 1/4 -&gt; 2   24ivide 1 by 2 :   =&gt; 2x/(x+4) = 8/5   =&gt; 5x = 4x + 16   =&gt; x = 16   =&gt; y = 5/2 *16= 
<gadget id="calculator">5/2 *16</gadget>
<output>40</output>
40   so x - y= 24   The answer is 24
<result>D</result>
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 1/4. What is the difference of the numerator and denominator of the original fraction?