Potty pooper read a 90-page book in 6 days it he keeps reading at that rate how long will it take him to read a 300- page book?

: explain your answer

90/6=15 so he read 15 pages a day. 300/15=20 so he would read a 300 page book in 20 days :)

The answer is 20 days.
Here's why:
We already know that potty reads a 90- page book in 6 days , we want to find how long it takes him/her to read a 300- page book.
Let's make a proportion:
90/300 6/x
X represents the total of days .
90 times x=90x
300 times 6=1800
1800 divided by 90x= 20
X= 20