You have a part time job. you work 3 hours on friday and 6 hours on saturday. you also receive an allowance of $20 per a week. you earn $92 per week. how much did you make at your part time job? how much did you make per a hour at your part time job? *

$92/week is the amount of money you gained from work combined with your $20/week allowance money. 

92 - 20 = 72 (total money made per week subtract allowance money leaves money made from work)
Thus, you make $72/week at your part time job.

You work a total of 9 hours. (3hrs on Fri & 6hrs on Sat added together)
72/9 = 8 (total amount of money made divided by the 9 hrs you worked for - gives amount of money you make per hour)
Thus, you make $8/hr at your part time job.

9/12 is the answer because 3/4 times 3 each is 9/12