Wednesday, September 2, 2015

P5 Average (an extension question by CCL)

James wrote a few numbers on a piece of paper and calculated the average of the value of these numbers.
If James wrote another, 10, on the paper, the average would be reduced by 1.
If he wrote the number 106 instead, the average would be increased by 3.

(a) How many numbers did he write on the piece of paper originally?
(b) What was the original average value?


Modified from