A test maker is to design a probability test from a list of 21 questions. The 21 questions are classified into three categories: hard, intermediate and easy. If there are 7 questions in each category and the test maker is to select two questions from each category, how many different combinations of questions can the test maker put on the test?
A) (7!/(5!2!))3
B) (7!/(5!))3
C) (7!/(2!))3
D) 3*29
E) 72
OA : A
A) (7!/(5!2!))3
B) (7!/(5!))3
C) (7!/(2!))3
D) 3*29
E) 72
OA : A
