The average of 11 results is 20. The average of first 5 of them is 15 and that of last 5 is 22 . Find the 6th result?  Choose the correct choice:
A) 35  B) 50  C) 100  D) 120  E) 150

Rationale: "6 th result = sum of 11 results - sum of 10 results = 11 * 20 - 5 * 15 - 5 * 22 = 220 - 75 - 110 = 35 answer is a"
Answer: A