Average Practice Test 7

Average of 18th inning = X
Total scores up to 18th inning = 18 X
A batsman scores 78 runs in the 19th inning
Average is decreased by 2.
By condition,
$\frac{18\mathit{X}+78}{19}=\mathit{X}-2$
$\Rightarrow \mathit{X}=116$
Average score after the 19th inning = X − 2 = 116 - 2 = 114