Question

Nine numbers are taken from calender as shown

9	10	11
16	17	18
23	24	25

If the sum of all given numbers is S, then the value of $\frac{S}{9}$ equals to

• A. 17

Answer 1

The correct option is A 17
Nine numbers as shown in the question can be written in the general form as

$x-8$	$x-7$	$x-6$
$x-1$	$x$	$x+1$
$x+6$	$x+7$	$x+8$

Now adding all the dates we get
$(x-8)+(x-7)+(x-6)+(x-1)+x+(x+1)+(x+6)+(x+7)+(x+8)=9x$

According to the data provided,
$S=9x\Rightarrow \frac{S}{9}=\frac{9x}{9}\Rightarrow \frac{S}{9}=x$

Hence, the value of $\frac{S}{9}$ is 17 in this case.