Question

Ask your friend — Write down your age. Add 5 to it. Multiply the sum by 2. Subtract 10 from it. Next divide it by 2. What do you get?
Is your friend surprised?

Answer 1

Let the age of my friend be 9 years.

Adding 5 to it, we get
9 + 5 = 14

Multiplying this sum by 2, we get
14 $\times$ 2 = 28

Subtracting 10, we get
28 − 10 = 18

Dividing it by 2, we get
$\frac{18}{2}=9$
After doing all the operations, we again get the age of our friend's age as the final answer.

Disclaimer: The answer may vary from student to student based on his/her observation. The answer provided here is only for reference.