A truck driver has to spend $2 per gallon of gas. She can drive 10 miles per gallon. She drives at a rate of 30 miles per hour. If she is paid $.50 per mile, how much money does she make if she drives for 10 hours?
Stream of thoughts:
90
The truck driver drives for 10 hours at 30 miles per hour, so she drives 10 * 30 = 300 miles.

Therefore, she needs 300 / 10 = 30 gallons of gas.

This will cost her 30 * $2 = $60.

She will make 300 * $.

50 = $150.

Thus, after paying for gas, she will make $150 - $60 = $90.

.

The answer is 90