The average of 21 data is 36 out of which the first 12 data are having an average of 15. The average of the rest 9 data is:
Answer & explanation
Correct answer: option 3
Let average of rest 9 data = A
ATQ ,
12 × 15 + 9 × A = 21 ×36
180 + 9A = 756
9A = 576
A = 64
So , Average of rest 9 data = 64