The average of 5 quantities is 11. The average of 3 of them is 4. What is the average of remaining 2 numbers? Choose the correct answer:  A) 21.5  B) 10.6  C) 8  D) 9.5  E) none of these

Rationale: "answer : a ( 5 x 11 - 3 x 4 ) / 2 = 21.5"
Answer: A