MAT Exam 2023 Paper

Concept:Let the original average be $x$. Then use the new total and new average to form an equation.Explanation:Let the average after 12 innings be $x$.Total runs in 12 innings $=12x$.In the 13th inning, he scores 96 runs.New total runs $=12x+96$.His average increases by 5, so the new average is $x+5$.Thus, $\frac{12x+96}{13}=x+5$.Multiplying both sides: $12x+96=13x+65$.So, $96-65=13x-12x$, giving $x=31$.Therefore, average after the 13th inning $=31+5=36$.Answer:36 runs per innings, i.e. Option C.