Jake's neighbors hire him to mow their lawn and plant some flowers. Mowing the lawn takes 1 hour and pays $15. If Jake wants to make $20/hour working for the neighbors, and planting the flowers takes 2 hours, how much should Jake charge (in total, not per hour) for planting the flowers?
First figure out how many hours total Jake works by adding the time spent mowing the lawn to the time spent planting flowers: 1 hour + 2 hours = 
<gadget id="calculator">1+2</gadget>
<output>3</output>
3 hours.
Then figure out how much money Jake makes if he earns $20/hour for three hours by multiplying the time spent by the pay rate: $20/hour * 3 hours = $
<gadget id="calculator">20*3</gadget>
<output>60</output>
60.
Then subtract the money Jake gets paid for mowing the lawn from the total to find how much he should charge in total for planting the flowers: $60 - $15 = $
<gadget id="calculator">60-15</gadget>
<output>45</output>
45.

<result>45</result>