50 boys and 100 girls are examined in a test; 50% of the boys and 40% of the girls pass. The percentage of the total who failed is ?  Choose the correct choice from the following answers:
A) 42.5 % B) 62.1 % C) 56.7 % D) 39.9 % E) 51.4 %

Rationale: "total number of students = 50 + 100 = 150 number of students passed = ( 50 % of 50 + 40 % of 100 ) = 25 + 40 = 65 number of failures = 85 * 100 / 150 = 56.7 % answer is c"
Answer: C