Question

Tom has three times as many pencils as pens but has a total of de 100 writing utensils. How many pencils and pens does toms have?

Answer 1

Tim has 75 pencils and 25 pens

Explanation:

To solve this create a system of equations. To do so, first create an equation for the total number of utensils that he has. Let x equal the number of pencils and y equal the number of pens.

x+ y = 100

Now make one for the comparison of the two and solve for the constant.

x = 3y

x - 3y = 0

Now to solve the system, multiply the second equation by -1 and add them together.

x + y = 100

-x + 3y = 100

-----------------

4y = 100

y = 25

Now that we have the number of pens, find the number of pencils using an equation.

x + y = 100

x + 25 = 100

x = 75