Two positive integers differ by 4, and sum of their reciprocals is 2. Then one of the numbers is Choices.
A) a) 3 B) 2 C) c) 5 D) d) 21 E) e) 28
Algebraic approach:   Let n be the smaller integer =&gt; 1/n + 1/(n+4) = 2   or ((n+4)+n)/n(n+4) =2 or (n^2+4n)*2 =2n+4 or n=2 as n cannot be -negative   Solve for n =&gt; n=2. Hence,   2
<result>B</result>
Two positive integers differ by 4, and sum of their reciprocals is 2. Then one of the numbers is