If the given two numbers are respectively 7% and 28% of a third number, then what percentage is the first of the second ?  Choose the correct answer
A) 20 %	B) 25 %	C) 18 %	D) 30 %	E) none of these

Rationale: "here , l = 7 and m = 28 therefore , first number = l / m x 100 % of second number = 7 / 28 x 100 % of second number = 25 % of second number answer : b"
Answer: B