Tony drives a car that gets 25 miles to the gallon. He drives 50 miles round trip to work 5 days a week. His tank holds 10 gallons. He begins the week with a full tank and when he runs out he fills up at the local gas station for $2 a gallon. How much money does Tony spend on gas in 4 weeks? Give the rationale and then the answer.
Let's think step by step. First, we need to determine how many miles Tony drives in 4 weeks. We do this by performing 50 * 5 = 250 miles per week. Next, we multiply the weekly total by 4 by performing 4 * 250 = 1000 miles in 4 weeks. Now, we need to find out how many times Tony needs to fill up his gas tank. His gas tank holds enough gas to last 25 * 10 = 250 miles. This means in 4 weeks, he needs to fill up his tank 1000 / 250 = 4 times. Since Tony's gas tank holds 10 gallons, this means he needs to pay for 4 * 10 - 40 gallons of gas in a month. Since gas costs $2 a gallon, this means Tony spends 40 * 2 = $80 on gas every month,.. The answer is: 80.

Rory collects rainwater. He has 100 L of rainwater in his tank. During a heavy rainstorm, water flows into the tank at a rate of 2 L/min for 90 minutes. How much water is in the tank at the end of the heavy rain? Give the rationale and then the answer.
Let's think step by step. During the heavy rain, the tank collects 2 * 90 = 180 L of water. The tank has a total of 100 + 180 = 280 L of water.. The answer is: 280.

Nancy agreed to pay 40% of the cost of her daughter's car insurance, which costs $80 a month. How much will Nancy pay each year? Give the rationale and then the answer.
Let's think step by step. First calculate Nancy's monthly portion of the car insurance by multiplying the total cost by 40%: .4 * $80 = $32. Then multiply the monthly cost by 12 to find the annual cost: $32 * 12 = $384.. The answer is: 384.