Of 440 surveyed students, 20% of those who read book A also read book B and 25% of those who read book B also read book A. If each student read at least one of the books, what is the difference between the number of students who read only book A and the number of students who read only book B?
Select the correct option:
A) 20  B) 25  C) 30  D) 35  E) 55

Rationale: "say the number of students who read book a is a and the number of students who read book b is b . given that 20 % of those who read book a also read book b and 25 % of those who read book b also read book a , so the number of students who read both books is 0.2 a = 0.25 b - - > a = 1.25 b . since each student read at least one of the books then { total } = { a } + { b } - { both } - - > 440 = 1.25 b + b - 0.25 b - - > b = 220 , a = 1.25 b = 275 and { both } = 0.25 b = 55 . the number of students who read only book a is { a } - { both } = 125 - 25 = 100 ; the number of students who read only book b is { b } - { both } = 275 - 55 - 220 ; the difference is 220 - 55 = 165 . answer : e ."
Answer: E