[Question]Alan likes to support music creators, so instead of downloading songs from the internet, he visits a record store once in a while. He decided now to buy 2 CDs by "The Dark", 1 CD by the creator "AVN", and 5 CDs that are mixes of songs from the 90s. The price of the "AVN" CD is $12 and it is half the price of one CD by "The Dark". The 5 CDs of 90s music cost is 40% of all the cost of all other CDs Alan is going to buy. How much will Alan have to pay for all the products?
[Answer]If one "AVN" is half the price of one "The Dark" CD, that means one CD of "The Dark" costs 12 * 2 = $24. So for two "The Dark" CDs, Alan needs to pay 24 * 2 = $48. So all CDs cost by now 12 + 48 = $60. The 90s music CDs cost 40 / 100 * 60 = $24. That means for all CDs Alan needs to pay 60 + 24 = $84. The answer is 84.

[Question]Jack leaves his bathtub's faucet dripping at a rate of 40 ml/minute. Water evaporates from the bathtub at a rate of 200 ml/hour. If he leaves the water running for 9 hours, then dumps out 12 liters, how many milliliters of water are left in the bathtub?
[Answer]First find how much water fills the bathtub per hour: 40 ml / minute * 60 minutes / hour = 2400 ml / hour. Then subtract the water that evaporates to find the total amount of water added per hour: 2400 ml / hour - 200 ml / hour = 2200 ml / hour. Then multiply that amount by the number of hours to find the total amount of water in the tub: 2200 ml / hour * 9 hours = 19800 ml. Then find the number of milliliters in 12 liters: 12 liters * 1000 ml / liter = 12000 ml. Then subtract the water Jack removes from the total amount of water to find the remaining amount of water: 19800 ml - 12000 ml = 7800 ml. The answer is 7800.

[Question]James streams on twitch. He had 150 subscribers and then someone gifted 50 subscribers. If he gets $9 a month per subscriber how much money does he make a month?
[Answer]He now has 150 + 50 = 200 subscribers. So he makes 200 * 9 = $1800 a month. The answer is 1800.

[Question]The electricity price in Coco's town is $0.10 per kW. Coco's new oven has a consumption rate of 2.4 kWh (kilowatt-hours). How much will Coco pay for using his oven only if he used it for a total of 25 hours last month?
[Answer]
If Coco used his oven 25 hours last month and its energy consumption is 2.4 kW per hour, then we consumed a total of 25 * 2.4 = 60 kW on his oven last month. If the price of electricity is $0.10 per kW, then 60 kW would cost = $0.10 * 60 = $6. The answer is 6.