Start with

Add 2x to both sides:

Subtract 21 from both sides:

Divide both sides by 5. Since it is positive, we don't have to change the inequality sign:

So, the answer is 
432 million, 540 times .20 equals 108, subtract 108 from 540 and you get your answer
Remark
The trick to this question is realizing what you took 1/3 of. Did you take it of the 150000 or is it 1/3 of some total you have to find. I don't think you could come up with a third choice.
It turns out that the answer is 1/3 of a number you don't know.
Equation
(1/3) x = 150000 Multiply both sides by 3
3*(1/3) x = 150000 * 3
x = 150000 * 3
x = 450000
Conclusion
The amount the company makes is 450000 dollars / year.
480 is 100%
48 = 10%
480 = 100%