Two positive integers differ by 4, and sum of their reciprocals is 1. Then one of the numbers is Choose the correct choice from the following answers:	A) 2	B) 1	C) 5	D) 21	E) 28

Rationale: algebraic approach : let n be the smaller integer = > 1 / n + 1 / ( n + 4 ) = 1 or ( ( n + 4 ) + n ) / n ( n + 4 ) = 1 or n ^ 2 + 4 n = 2 n + 4 or n = 2 as n can not be - negative solve for n = > n = 2 . hence , a
Answer: A