The average of runs of a cricket player of 10 innings was 36. How many runs must he make in his next innings so as to increase his average of runs by 4 ?	Choose the correct choice
A) 76	B) 80	C) 85	D) 87	E) 89

Rationale: "explanation : average = total runs / no . of innings = 36 so , total = average x no . of innings = 36 x 10 = 360 . now increase in avg = 4 runs . so , new avg = 36 + 4 = 40 runs total runs = new avg x new no . of innings = 40 x 11 = 440 runs made in the 11 th inning = 440 - 360 = 80 answer : b"
Answer: B