Question

The monthly salary of a show room attendant is the sum of a fixed salary of $600 plus 8% of all monthly sales. What should the monthly sales be so that her monthly salary reaches $1,800?
$15,000
$18,000
$20,000
$22,000

Answers

GPT-4o mini
Let \( S \) be the monthly sales. The monthly salary \( M \) of the showroom attendant can be expressed as:

\[
M = 600 + 0.08S
\]

We want to find \( S \) when the monthly salary \( M \) is $1,800:

\[
1800 = 600 + 0.08S
\]

Subtract 600 from both sides:

\[
1800 - 600 = 0.08S
\]

\[
1200 = 0.08S
\]

Now, divide both sides by 0.08 to solve for \( S \):

\[
S = \frac{1200}{0.08}
\]

Calculating the right side:

\[
S = 1200 \div 0.08 = 1200 \times 12.5 = 15000
\]

Thus, the monthly sales should be:

\[
\boxed{15000}
\]