Question

A person sleeps for 8 hours a day. A 60 years old person must have slept for how many years?​

Answer 1

Solution:

There are 24 hours in a day. 8 hours is $\frac{8}{24}$ part of 1 day.
$\frac{8}{24}$ = $\frac{8÷8}{24÷8}$ = $\frac{1}{3}$

So he spent $\frac{1}{3}$ part in 1 day for sleeping.
In 60 years he would spent $\frac{1}{3}$ ×60 years
= 60 years ÷ 3 = 20 years