If 75 % of a boys answered the first question on a certain test correctly, 55 % answered the second question on the test correctly, and 20 % answered neither of the questions correctly, what % answered both correctly?  Pick: A) 10 % B) ( 8 ) 20 % C) 50 % D) 60 % E) 65 %

Rationale: { total } = { first } + { second } - { both } + { neither } 100 % = 75 % + 55 % - { both } + 20 % - - > { both } = 50 % . answer : c
Answer: C