Explanation:

Sol. Ans.(c).

Regular method:Average of 50 innings = 46.4.

Sum of 50 innings = 50 × 46.4 = 2320 …(i)

Average of 60 innings = 46.4 + 2.6 = 49

Sum of 60 innings = 60 × 49 = 2940 …(ii)

So runs scored in last ten innings = 2940 – 2320 = 620.

Average = 620/10 = 62. So the correct option is (c).

Short-cut: The runs scored in last ten innings increase the average of all 60 innings. It means that in last ten innings 2.6×60 more runs were scored.

So, in last ten innings total runs scored = 10 × 46.4 (previous average) + extra runs which caused the increase in the average of all 60 innings

= (10 × 46.4) + (2.6 × 60) = 464 + 156 = 620.

So required average 620/10 = 62.