Question

Mirabelle makes a salary of $2,000 per month with a 25% commission on her sales. She has decided to save 5% of her salary and 10% of her commission earnings every month for retirement. Which of the following equations gives the monthly amount, S(x), that she deposits into her retirement account as a function of x, her total monthly sales?

Answer 1

Mirabelle deposits 5% of her salary, which has a constant value of $2000, so we have:

$5\text{\% of 2000}=\frac{5}{100}\cdot2000=5\cdot20=100$

She also deposits 10% of her commission, which is calculated as 25% of her sales.

So, if the total value of her sales is given by x, we have:

$10\text{\% of (25\% of x)}=\frac{10}{100}\cdot\frac{25}{100}\cdot x=\frac{1}{10}\cdot\frac{1}{4}\cdot x=\frac{x}{40}=0.025x$

Therefore, adding both deposits, we have:

$S(x)=0.025x+100$

So the correct option is D.