NIACL Model Paper 1 with solutions for free online practice

(b) Let the average of 5 innings = x
Score in sixth innings = 80
∴Total of 5 innings = 5x
According to the question,
$\frac{5\mathit{x}+80}{6}=\mathit{x}+5$
⇒$5\mathit{x}+80=6\mathit{x}+30$
⇒$\mathit{x}=80-30=50$
∴His average after six innings = 50 + 5 = 55