A batsman in his 13th inning makes a score of 97 runs, thereby increasing his average score by 5. What is his average score after the 13th inning?
- 77
- 67
- 37
- 57
Sol:
A batsman in his 13th inning makes a score of 97 runs, thereby increasing his average score by 5.
Old average × old number + something = New average × new number
Let his old average (i.e. average till 12th innings) be ‘x’ ⇒ New average is ‘x + 5’ [∵ Average increased by 5]
∴ x × 12 + 97 = (x + 5) × 13
⇒ 12x + 97 = 13x + 65
⇒ x = 32
∴ New Average = x + 5 = 32 + 5 = 37
