Number of pencils in each box problem

Sergio had 8 colored pencils. He bought 3 more boxes of colored pencils. Sergio now has 35 colored pencils. If each box had the same number of pencils, how many pencils were in each box?

Solution

Number of pencils Sergio had + number of pencils purchased is equal to number of pencils he has now.

Let p be the number of pencils in each box

Let 8 be the number of pencils Sergio had

Let 35 be the number of pencils Sergio has now


Number of pencils purchased = 3 × p

Number of pencils purchased = 3p

Number of pencils Sergio had + number of pencils purchased is equal to number of pencils he has now.

The statement above gives the following equation

8 + 3p = 35

8 - 8 + 3p = 35 - 8

0 + 3p = 35 - 8

3p = 35 - 8

3p = 27

Divide both sides by 3

3p/3 = 27/3

p = 9

There are 9 pencils in each box