Stephanie sells 12 pretzels per hour. Robert sells 15 pretzels per hour. This week, Robert sold an additional 18 pretzels. Which of the following expressions represents the total sales of both people this week, where S represents the number of hours that Stephanie worked and R represents the number of hours that Robert worked?

Question

A.
12
S
+
15
R
+
18

B.
15
S
+
12
R
+
18

C.
12
S
+
18
R

D.
12
S
+
15
R

Answer 1

To represent the total sales of both Stephanie and Robert, we need to consider the number of pretzels each person sells and the additional pretzels that Robert sold this week.

• Stephanie sells 12 pretzels per hour, so in \( S \) hours, she sells \( 12S \) pretzels.
• Robert sells 15 pretzels per hour, so in \( R \) hours, he sells \( 15R \) pretzels. Additionally, Robert sold an extra 18 pretzels, so we need to add this to his total sales.

Thus, the total sales for both Stephanie and Robert this week would be: \[ 12S + 15R + 18 \]

So the correct expression is:

A. \( 12S + 15R + 18 \)