A batsman has a certain average runs for 15 innings. In the 16th inning he made a score of 60 runs and thereby decrease in average by 4. His average after 16th inning is :
1). 127
2). 145
3). 120
4). 210
Let the batsman’s average runs for 15 innings be x.
Then, the total runs scored by batsman in 15 innings = 15x
Since, he scored 60 runs in his 16th inning
Total runs scored by batsman in 16 innings = 15x + 60
Thus, according to question
New average for 16 innings = (x - 4) runs
Therefore, x - 4 = (15x + 60)/16
⇒16(x - 4) = 15x + 60
⇒16x - 64 = 15x + 60
∴ x = 124
∴ New average for 16th innings = (x - 4) runs = 124 - 4 = 120 runs.