To work through this problem, we can first calculate how much money Joe earned at regular pay: 40 (number of hours) x 13.5 (pay rate) = 540 (in dollars)
Now, before we figure out how much he earned working overtime, we must calculate his overtime pay rate (time and a half). We do this by multiplying his normal pay rate by 1.5: 13.5 x 1.5 = 20.25 ($/hr.)
Now we can calculate his overtime total: 8 (number of hours) x 20.25 (overtime pay rate) = 162 (in dollars)
So, to find the total amount of money Joe earned, we have to add the two totals together: