Question: Derek has $40. He spends $14 on lunch for himself, $11 for lunch for his dad, and $5 on more lunch for himself. His brother Dave has $50 and only spends $7 on lunch for his mom. How much more money does Dave have left than Derek?
Answer: Derek has 40 - 14 - 11 - 5 = 10 dollars left. Dave has 50 - 7 = 43 dollars left. Dave has 43 - 10 = 33 more dollars left than Derek. The answer is 33.
[Question]Peggy has 6 dolls. Her grandmother gives Peggy her own collection of 30 dolls. Over the year, Peggy receives half that amount of dolls between her birthday and Christmas. How many dolls does Peggy now have?
[Answer]Peggy has 6 dolls and her grandmother gave her 30 so that's 6 + 30 = 36 dolls. Over the holidays, Peggy is gifted half the number of dolls her grandmother gave her, so she receives 30 / 2 = 15 more dolls. Peggy had 36 dolls and received another 15 for a total of 36 + 15 = 51 dolls. The answer is 51.
Q: In the post-apocalyptic wasteland, 1 lizard is worth 8 bottle caps, 3 lizards are worth 5 gallons of water, and 1 horse is worth 80 gallons of water. Marla can scavenge for 20 bottle caps each day, but needs to pay 4 bottle caps per night for food and shelter. How many days does it take Marla to collect all the bottlecaps she needs to buy a horse?
A: First find how many lizards you get for one gallon of water: 3 lizards / 5 gallons = .6 lizards / gallon. Then figure out how many lizards 80 gallons of water is worth: 80 gallons * .6 lizards / gallon = 48 lizards. Then figure out how many bottle caps 48 lizards is worth: 48 lizards * 8 bottle caps / lizard = 384 bottle caps. Then figure out how many bottle caps Marla can save each day by subtracting the number she spends from the number she finds: 20 bottlecaps / day - 4 bottlecaps / day = 16 bottlecaps / day. Finally, divide the number of bottle caps Marla needs by the number she saves each day: 384 bottle caps / 16 bottle caps / day = 24 days. The answer is 24.
Question: Christina and her friend are driving across the state. When Christina is driving the speed limit is 30 miles per hour. When her friend is driving, the speed limit is 40 miles per hour. The drive is 210 miles total. If her friend drives for 3 hours and both drive at the speed limit, how many minutes will Christina drive?
Answer: The friend drives 40 * 3 = 120 miles. Thus, Christina drives 210 - 120 = 90 miles. Since the speed limit is 30 miles per hour when Christina is driving, she drives for 90 / 30 = 3 hours. Thus, she drives for 3 * 60 = 180 minutes. The answer is 180.
[Question]Mike changes tires on different vehicles. He changes all the tires on 12 motorcycles and all the tires on 10 cars. How many tires did he change?
[Answer]He changed 12 * 2 = 24 motorcycle tires. He changed 10 * 4 = 40 car tires. So he changed 24 + 40 = 64 total tires. The answer is 64.
[Question]Janet starts driving across a lake in a speedboat going 30 miles per hour. Her sister follows in a sailboat that has a speed of 12 miles per hour. If the lake is 60 miles wide, how long does Janet have to wait on the other side for her sister to catch up?
[Answer]
First find how long it takes Janet to cross the lake: 60 miles / 30 miles / hour = 2 hours. Then find how long it takes her sister to cross the lake: 60 miles / 12 miles / hour = 5 hours. Then subtract Janet's travel time from her sister's travel time to find the difference: 5 hours - 2 hours = 3 hours. The answer is 3.