The average of 10 numbers was calculated as 17. It is discovered later on that while calculating the average, one number, namely 56, was incorrectly read as 26. What is the correct average?	Pick one
A) 19  B) 20  C) 21  D) 22  E) 23

Rationale: 10 * 17 - 26 + 56 = 200 200 / 10 = 20 the answer is b .
Answer: B