After collecting all the old electronics in their house, Lauryn made $2000 from selling the items on eBay. If her friend Aurelia also made 70% of what she sold on eBay after selling her used electronics, calculate the total amount of money the two friends made on eBay. Give the rationale and then the answer.
Let's think step by step. If Lauryn made $2000 from eBay, then her friend made 70 / 100 * $2000 = $1400. In total, the two friends made $2000 + $1400 = $3400.. The answer is: 3400.

Matilda has half as many jellybeans as Matt. Matt has ten times as many jellybeans as Steve. If Steve has 84 jellybeans, how many jellybeans does Matilda have? Give the rationale and then the answer.
Let's think step by step. Matt has 84 * 10 = 840 jellybeans. Matilda has 840 / 2 = 420 jellybeans.. The answer is: 420.

Tom decides to lease a car. He drives 50 miles on Monday, Wednesday, and Friday, and Sunday for the rest of the days he drives 100 miles. He has to pay $.1 per mile he drives. He also has to pay a weekly fee of $100. How much does he have to pay in a year. Give the rationale and then the answer.
Let's think step by step. He does the long drive 7 - 4 = 3 days a week. So he drives a total of 4 * 50 + 3 * 100 = 500 miles a week. That means the car cost 500 * .1 = $50 just for the mileage per week. So he pays 100 + 50 = $150 per week for the car. That means the total cost of the car is 150 * 52 = $7800 a year.. The answer is: 7800.