Let x be the hourly rate. Since he works 20 hours that week, the hourly wages are given by 20x. We add to that his commission, which is 16% of the $1500 in sales, or 0.16(1500). This totals to 515:
20x + 0.16(1500) = 515 20x + 240 = 515
Subtract 240 from both sides: 20x + 240 - 240 = 515 - 240 20x = 275
Divide both sides by 20: 20x/20 = 275/20 x = 13.75.
To determine this, we need to set up fractional proportions. First, put 12.5% (what we're looking for) over 100%, which is the total (256). 12.5/100 should be your first fraction. Now, put x over 256, x being 12.5% of 256. x/256 should be your second fraction. Now put these two fractions as an equation. x/256 = 12.5/100 This may be where things get tricky if you don't pay attention. Cross multiply the top number (numerator) of x/256 with the bottom number (denominator) of 12.5/100. You should end up with 100x. Now, cross multiply the top number of 12.5/100 with the bottom number of x/256. You should end up with 3200. Now our equation is: 100x = 3200 Divide both sides by 100 to get x. 100x/100 = x 3200/100 = 32 x = 32 is now your simplified equation. Your final answer is: 32 is 12.5% of 256. Also, since 12.5% is 1/8 of 100%, we can test our answer. Multiply 32 by 8 to get 8/8 (100%). 32 x 8 = 256. Your answer is 32. I hope this helps!