Question

If I make $7.25 a hour and I work for three days how much money is that every two weeks

Answer 1

I am pretty sure it would be $43.50 every two weeks because $7.25 x 3 is 21.75 and then for two weeks add 21.75 +21.75

Answer 2

There are a couple of things you didn't mention. 
In order to come up with an answer to the question,
I have to assume reasonable numbers for them, and
then answer the question that I have invented.

Assumption #1:  Each day that you work, you work for 8 hours.

Assumption #2:  You work for three days each week.

If those assumptions are true, then you earn

  ($7.25 / hour) x (8 hours/day) x (3 days/week) x (2 weeks)  =

       ($7.25 x 8 x 3 x 2)  =  $348  before taxes and other deductions.