Test 7 Section 3: #8
Let’s work backwards on this. If he saves 90% of his earnings, Ken needs to make $300 to save $270:
He makes $80 for the first 10 hours he works, so he needs to make $220 more to get to $300.
He’s making $10/hour for that last $220, so he’s going to have to work 22 more hours.
Of course, we can also construct an equation to solve this. First, as above, we know Ken worked for 10 hours at $8/hour, so for that time he made $80.
He’s making $10/hr for the rest of the week. We don’t know how many hours, so let’s use h for hours. He’ll make 10h dollars for the rest of the week.
That means in total he’ll make dollars for the week.
He’s going to save 90% of what he makes, so his savings will be .
He wants to save $270, so the equation we need to solve is :