Examveda

# The average of the first five multiples of 9 is:

A. 20

B. 27

C. 28

D. 30

### Solution(By Examveda Team)

\eqalign{ & {\text{Required}}\,{\text{average}} \cr & = {\frac{{{\text{total}}\,{\text{sum}}\,{\text{of}}\,{\text{multiple}}\,{\text{of}}\,9}}{5}} \cr & = {\frac{{9 + 18 + 27 + 36 + 45}}{5}} \cr & = 27 \cr}
Note that, average of 9 and 45 is also 27.
And average of 18 and 36 is also 27.

1. 9(1,2,3,4,5)/5 = 9*5(5+1)/2/5 9*6/2

2. Another method for this ,

Avg= first term + last term /2
hence, 9+45/2=27

3. 9×15/5=9×3
=27

4. 9+45/2
=27

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