The average score of a cricketer for ten matches is 38.9 runs. If the average for the first six matches is 42, what is the average for the last four matches?
34.25
36.4
40.2
32.25
Explanation:
Total runs scored in 10 matches = $10 \times 38.9$
Total runs scored in first 6 matches =$ 6 \times 42$
Total runs scored in the last 4 matches =$ 10 \times 38.9 - 6 \times 42$
Average of the runs scored in the last 4 matches = $\dfrac{10 \times 38.9 - 6 \times 42}{4}$
$=\dfrac{389 - 252}{4}$
$=\dfrac{137}{4}$
$= 34.25$