Question

Mustafa contributes 11% of his $67,200 annual salary to his 401(k) plan. What is his pretax income?

Answer 1

You have to subtract the 11% that you are putting into your 401k to find out how much you are earning and that you're not putting into retirement.

67,200*0.11 = 7,392

67,200 - 7,392 = 59,808

Answer 2

11% of $67,200.
We need to keep in mind that some words and numbers here aren't important, like 401(k) plan. 
So what is 11% of $67,200?

$\frac{11}{100} * 67,200$

$11* 672$

$7392

Hope this helps!