Correct Answer - Option 4 : 24
Given: A cricketer scored 48 runs in the 7th innings. His average score increased by 4.
Formula: Average of n numbers a1, a2, ... an = (a1 + a2 + ... + an)/n
Calculation: Let his average up to 7th innings be x
(6x + 48)/7 = x + 4
⇒ 6x + 48 = 7x + 28
⇒ 20 = x
So, his average after 7th innings is 20 + 4 = 24