Mark bought a notebook for $1.45 and some pencils for $0.42 each. If the total cost was $6.91, how many pencils did he buy?

A. 12

B. 13

C. 14

D. 15

B - 13

Okay, we know that Mark brought 1 notebook and the totally is 6.91 while one pencil costs $0.42.

x = number of pencils he brought.

we know the price of 1 notebook + the cost of pencils times the numbers of pencils he brought = total cost.

So the equation will be:

1.45 + 0.42x = 6.91 subtract 1.45 on both sides.

0.42x = 5.46 Then we solve for x by dividing both sides by 0.42

x = 13

So the number of pencils he brought is 13.

1. 6.91 - 1.45 = 5.46

You subtract the notebook from the total cost

2. 5.46 / 0.42 = 13

You divide the cost of a pencil from the left over amount of money to see how many pencils Mark bought

3. Mark bought 13 pencils