Q: Mandy’s phone data plan charges $30 per month for data. Her first month, she got a promotional rate of one-third the normal price. However, in the fourth month she went over her data limit and was charged an extra fee of $15. How much did Mandy pay in the first 6 months for data?
A: Mandy paid 1 / 3 * 30 = 30 / 3 = $10 for her first month of data. She paid 30 + 15 = $45 for her fourth month of data. Minus those two months, she had 6 - 2 = 4 months of regular charges. Thus, Mandy paid 4 * 30 + 10 + 45 = 120 + 55 = $175 for the first 6 months for data. The answer is 175.

Q: Bob has to hire someone to fix his garden. A storm destroyed all 20 of his rose bushes. He decides to replant all the rose bushes. Each rose bush costs $150. He also needs to pay a gardener $30 an hour, 5 hours each day for 4 days. The final expense is 100 cubic feet of soil sold for $5 per cubic foot. How much did the entire gardening project cost?
A: The roses cost 150 * 20 = $3000. The gardener works 4 * 5 = 20 hours. So the gardener charges 30 * 20 = $600. The soil added another 5 * 100 = $500. So in total the cost was 3000 + 600 + 500 = $4100. The answer is 4100.

Q: Mr. Lu owns a computer store. For last month, half of their sales are laptops, one-third are netbooks, and the rest are desktop computers. If Mr. Lu's store was able to sell a total of 72 computers, how many of them are desktop computers?
A:
There were 72 / 2 = 36 laptops sold. There were 72 / 3 = 24 netbooks sold. So, there were a total of 36 + 24 = 60 laptops and netbooks sold. Thus, 72 - 60 = 12 desktop computers were sold last month. The answer is 12.