[Question]The capacity of Karson's home library is 400 books. If he currently has 120 books, how many more books does he have to buy to make his library 90% full?
[Answer]When 90% full, Karson's library holds 90 / 100 * 400 = 360 books. If he has 120 books in the library now, he needs to buy 360 - 120 = 240 books to make his library 90% full. The answer is 240.
Q: Haley is making cider. It takes 20 golden delicious apples and 40 pink lady apples to make one pint of cider. Each of her 6 farmhands can pick 240 apples per hour and will work 5 hours today. How many pints of cider can Haley make with the apples gathered today, provided that the ratio of golden delicious apples to pink lady apples gathered is 1:2?
A: First figure out how many apples total are needed for one pint of cider: 20 golden delicious / pint + 40 pink lady / pint = 60 apples / pint. Then multiply that number by 8 to find the number of apples needed for a gallon of cider: 60 apples / pint * 8 pints / gallon = 480 apples / gallon. Now find how many apples per hour all 8 farmhands pick: 240 apples / hour / farmhand * 6 farmhands = 1440 apples / hour. Then multiply that amount by the number of hours worked to find the total number of apples gathered: 1440 apples / hour * 5 hours = 7200 apples. Divide the total number of apples gathered by the number of apples used by gallon to find the number of gallons of cider made: 7200 apples / 480 apples / gallon = 15 gallons. Since there are 8 pints in a gallon, the final answer is 15 gallons * 8 pints / gallon = 120 pints. The answer is 120.
Question: Karen is paddling her canoe up a river against the current. On a still pond, Karen can paddle 10 miles per hour. The river flows in the opposite direction at 4 miles per hour. If the river is 12 miles long, how many hours will it take Karen to paddle up it?
Answer: First find Karen's net speed by subtracting the speed of the current: 10 mph - 4 mph = 6 mph. Then divide the length of the river by Karen's speed to find how long it takes her to paddle up it: 12 miles / 6 mph = 2 hours. The answer is 2.
[Question]Samuel took 30 minutes to finish his homework while Sarah took 1.3 hours to finish it. How many minutes faster did Samuel finish his homework than Sarah?
[Answer]Since there are 60 minutes in 1 hour, then 1.3 hours is equal to 1.3 x 60 = 78 minutes. Thus, Samuel is 78 – 30 = 48 minutes faster than Sarah. The answer is 48.
Q: Jenny wants to sell some girl scout cookies and has the choice of two neighborhoods to visit. Neighborhood A has 10 homes which each will buy 2 boxes of cookies. Neighborhood B has 5 homes, each of which will buy 5 boxes of cookies. Assuming each box of cookies costs $2, how much will Jenny make at the better choice of the two neighborhoods?
A: First, we need to determine which neighborhood is the better choice by comparing the number of boxes sold. A has 10 houses which will buy 2 boxes each, meaning A will give Jenny 10 * 2 = 20 box sales. Neighborhood B has 5 homes which will each buy 5 boxes, meaning she will sell 5 * 5 = 25 boxes by going to that neighborhood. Since 25>20, this means Jenny should choose neighborhood B. Since Jenny earns $2 per box sold, this means she will earn 25 * 2 = 50 dollars by choosing neighborhood B. The answer is 50.
Question: A parking area near Peter's house is 4 stories tall. There are 4 open parking spots on the first level. There are 7 more open parking spots on the second level than on the first level, and there are 6 more open parking spots on the third level than on the second level. There are 14 open parking spots on the fourth level. How many open parking spots are there in all?
Answer:
The number of open parking spots on the second level is 4 spots + 7 spots = 11 spots. The number of open parking spots on the third level is 11 spots + 6 spots = 17 spots. There are 4 spots + 11 spots + 17 spots + 14 spots = 46 open parking spots in all. The answer is 46.