Question

The number of hours left in the day are double of the number of hours already passed. How many hours have already passed in the day?

Answer 1

Hint - To solve this problem, firstly we have to read the problem carefully and collect the given information and then taking one quantity as x, we will be forming equations which will help us in solving our query and hence we will be approaching our answer.

Complete step-by-step solution -
Number of hours left in the day are twice the number of hours already passed.
Let the number of hours left in a day be x hours.
So, the number of hours left in the day will be =$2 \times (24 - x)$
As we know that the total number of hours in a day= 24.
It is a question of simple algebraic calculations where we suppose the condition given to us i.e the time left and accordingly formulate an equation out of it.
Then, at last we will reach the final answer.
No, of hours left$ = x$
$\therefore \,\,\,x = 2\left( {24 - x} \right)$
($\because $ one day $ = 24hrs$)
$x = 48 - 2x$
$\Rightarrow 8x = 48$
$\Rightarrow 3x = 48$
$\Rightarrow x = 16$
Hence the no. of hours passed
$ = 24 - x \\
   = 8\,hours \ $

Note - We Know that in a day there are$24$ hours. So, by assuming $x$ as the time left, we assumed and put it in the equation as per the question asked. It is a question of simple algebraic calculations where we need to suppose the condition given to us, i.e. the time left and accordingly formulating an equation out of it. This information is very useful in solving these kinds of questions.