The difference between the value of a number increased by 12.5% and the value of the original number decreased by 25% is 30. What is the original number W?  Choose one: A) 60 B) 80 C) 40 D) 120 E) 160

Rationale: "( 1 + 1 / 8 ) x - ( 1 - 1 / 4 ) x = 30 ( 9 / 8 ) x - ( 3 / 4 ) x = 30 x = 80 = w answer : b"
Answer: B