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

A. 20

B. 27

C. 28

D. 30

**Answer: Option B **

__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.

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9,18,27.36,45

Avg = 1st + Last / 2

(9+45)/2 = 27

RJ Champ

Ans = 9(1+2+3+4+5)/5

(1st +last term) / 2

(9+45) / 2

= 54/2

=27

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

Another method for this ,

Avg= first term + last term /2

hence, 9+45/2=27

9×15/5=9×3

=27

9+45/2

=27