Question

There are 90 pages in a book. Venu read 30% of it in 1 hour. How many pages of the book didn’t read in that hour?

Answer 1

Hint:To solve the question at first we must have a simple idea about percentage. At first, we have to convert the given percentage into a fraction. Then we will find out the number of unread read pages by multiplying the obtained fraction to 90. Then we subtract the obtained value from the total number of pages in the book to get the required answer.
We know that a percentage is a number or ratio that represents a fraction of 100. For example 20% represents the fraction\[\dfrac{{20}}{{100}}\]or the decimal 0.2.
Similarly 30% represents\[\dfrac{{30}}{{100}} = \dfrac{3}{{10}}\].

Complete step by step answer:
Given the total number of pages are 90.
According to question, Venu read 30% of the book that means Venu read 30 out of every 100 pages. Now the number of pages that Venu readout of total 90 pages is \[\dfrac{3}{{10}}\]of 90.
\[\dfrac{3}{{10}} \times 90 = 27\]
Now the unread pages left from the total pages is \[90 - 27 = 63\].
Therefore Venu didn’t read 63 pages in that hour.

Note:
 An alternative method we can find out \[(100 - 30)\% = 70\% \]of 90 to get required answer. A percentage is a dimensionless number that has no unit of measurement. Generally, many percentage values are between 0 and 100, There is no mathematical restriction For example, the percentage may include other values like 110% or \[ - 25\% \].