A batsman scores 87 runs in the 21st match of his career. His average runs per match increase by 2. What was his average before the 21st match ?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 ie 45.
Sum of scores till 20 matches = x
Average of 20 matches = y
x = 20y
(x + 87)/21 = y + 2
20y + 87 = 21y + 42
y = 45