If 85 percent of the test takers taking an old paper and pencil GMAT exam answered the first question on a given math section correctly, and 80 percent of the test takers answered the second question correctly, and 5 percent of the test takers answered neither question correctly, what percent answered both correctly?  Answers
A) 60 %
B) 65 %
C) 70 %
D) 75 %
E) 80 %

Rationale: "{ total } = { first correctly } + { second correctly } - { both correctly } + { neither correctly } 100 = 85 + 80 - { both correctly } + 5 { both correctly } = 70 . answer : c ."
Answer: C