Question

from 86 books to 150 books in percent increase

Answer 1

150 minus 86.Then the answer which is 64 you put it over the first set of books which was 86 ,multiplied by 100 over one then you cancel out any numbers that can be cancelled .And the what you get will be your answer.
so basically its 64 over 86 x 100 over one . hope that helped!

Answer 2

we know that

$86$ books represent the $100$%

Find the percentage of $150$ books

by proportion

$\frac{86}{100}\frac{books}{percentage} =\frac{150}{x} \frac{books}{percentage} \\\\ 86*x=150*100$

$x= 174.42$%

Find the percentage increase

Percentage increase=$174.42-100=74.42$%

therefore

the answer is

The percentage increase is $74.42$%