Q: Penny has $20. Penny buys 4 pairs of socks for $2 a pair and a hat for $7. How much money does Penny have left?
A: Penny buys 4 pairs of socks for $2 x 4 = $8. In total, Penny spent $8 + $7 = $15 on 4 pairs of socks and a hat. Penny has $20 - $15 = $5 left after buying 4 pairs of socks and a hat. The answer is 5.
Question: Mark has two pets, a hare that runs 10 feet/second and a turtle that crawls 1 foot/second. If they're going to run a 20 foot-race, how much of a head start (in seconds) does the turtle need to finish in a tie?
Answer: We can find how long the hare spends running by dividing the distance of the race by the hare's speed: 20 feet / 10 feet / second = 2 seconds. We can do the same for the turtle: 20 feet / 1 foot / second = 20 seconds. Finally, subtract the hare's run time from the turtle's run time to find the length of the head start the turtle needs: 20 seconds - 2 seconds = 18 seconds. The answer is 18.
[Question]Lake Crystal has twenty percent fewer frogs than Lassie Lake. If Lassie Lake has forty-five frogs, how many frogs are there in total in the two lakes?
[Answer]Lake Crystal has twenty percent fewer frogs than Lassie Lake, a total of 20 / 100 * 45 = 9 frogs. The total number of frogs in Lake Crystal is 45 - 9 = 36. Together, the two lakes have 36 + 45 = 81 frogs. The answer is 81.
Q: Bobby needs to buy a new pair of fancy shoes. He decides to go to a cobbler and get them handmade. The cobbler charges $250 to make the mold. He then charges $75 an hour for 8 hours to make the shoes. The cobbler agrees to only charge 80% of the cost for work to make the shoes, since it is his first pair of shoes. How much did Bobby pay?
A: The cost of labor is 75 * 8 = $600. So Bobby pays 600 * .8 = $480. So that means Bobby pays 480 + 250 = $730. The answer is 730.
Question: In a city, the number of people living per cubic yard is 80. How many more people are in a city with 9000 cubic yards than a city with 6400 cubic yards?
Answer: The difference in cubic yards between the two cities is 9000 - 6400 = 2600 cubic yards. Since the number of people living in a city per cubic yard is 80, there are 80 * 2600 = 208000 more people living in a city with 9000 cubic yards than a city with 6400 cubic yards. The answer is 208000.
Q: John decided to start rowing around a square lake. Each side of the lake is 15 miles. Jake can row at twice the speed he can swim. It takes him 20 minutes to swim 1 mile. How long, in hours, does it take to row the lake?
A:
The perimeter of the lake is 4 * 15 = 60 miles. He swims at a speed of 60 / 20 = 3 mph. So he rows at a speed of 3 * 2 = 6 mph. That means it takes him 60 / 6 = 10 hours to row around the lake. The answer is 10.