A contractor has orders to build five houses. The contractor has a reputation for excellence, so the customers will wait as long as necessary for their houses. The revenue to the contractor (in multiples of $1000) and time (in days) to build each house is: 

Assuming they can only work on one house at a time, what would be an appropriate measure to schedule building the houses? Using this measure, what schedule should the contractor use?

House Cost 1 3 145 290 910 1150 2000 Time 15 20 40 45 100