There are 9 + 12 = 21 students in a class. Hence, 21 / 3 = 7 groups are formed.
The answer: 7
Reverse engineering the question: There are 9 boys and 12 girls in a class. The teacher needs to create groups with three members for their class activity. How many groups are formed?
Reasoning and answer: First night:320(1 / 4) = 80. 320 - 80 = 240. Second night:240(1 / 6) = 40. 240 - 40 = 200. Third night:200(.30) = 60. 200 - 60 = 140 ducks remain.
The answer: 140
What was the question?
Question: There are 320 ducks in a pond. On the first night 1/4 of them get eaten by a fox. On the second night 1/6 of the remaining ducks fly away, and on the third night 30 percent are stolen. How many ducks remain after the three nights?
First, find the total number of blocks south Janet is from her starting point by subtracting the blocks she walked north from the blocks she walked south: 8 blocks - 3 blocks = 5 blocks. Then find the number blocks she walked west: 3 blocks * 7 = 21 blocks. Then find the number of blocks she walked east: 8 blocks * 2 = 16 blocks. Subtract the number of blocks she walked east from the number of blocks she walked west to find how many blocks west of her starting point she is: 21 blocks - 16 blocks = 5 blocks. Add the number of blocks she needs to walk north to the number of blocks she needs to walk east: 5 blocks + 5 blocks = 10 blocks. Finally, divide the distance she needs to walk by her speed to find how long she'll spend walking: 10 blocks / 2 blocks / minute = 5 minutes.
The answer: 5
Reverse engineering the question: Janet lives in a city built on a grid system. She walks 3 blocks north, then seven times as many blocks west. Then she turns around and walks 8 blocks south and twice as many blocks east in the direction of her home. If Janet can walk 2 blocks/minute, how long will it take her to get home?
Reasoning and answer: The total lead time for the cargo is 21 days on water + 4 in customs + 7 to the warehouse or 21 + 4 + 7 = 32 days. If the warehouse is expecting the cargo in 2 days from today then the cargo should have already completed 32 - 2 = 30 days of lead time.
The answer: 30
What was the question?
Question: A cargo ship moving from Shanghai to Vancouver navigates for 21 days before reaching port. Customs and regulatory processes in Vancouver last 4 days. Finally, moving the cargo from the port to your rural warehouse takes some time and it always arrives on the seventh day. How many days ago should the ship have departed if your warehouse is expecting the shipment 2 days from today?
The car drives 180 miles in 4 hours, so its average speed is 180 miles / 4 hours = 45 miles per hour. In the next 3 hours, the car will drive 45 miles / hour * 3 hours = 135 miles.
The answer: 135
Reverse engineering the question: A car driving cross-country traveled 180 miles in 4 hours. At this rate of speed, how many miles further will the car travel in the next 3 hours?
Debbie used 4 * 2 = 8 feet of tape for the large boxes. She used 2 * 8 = 16 feet of tape for the medium boxes. She used 1 * 5 = 5 feet of tape for the small boxes. There were 2 + 8 + 5 = 15 boxes in all. She used 1 * 15 = 15 feet of tape for the address labels. Thus, she used 8 + 16 + 5 + 15 = 44 feet of tape in all.
The answer: 44
Reverse engineering the question:
Debbie works at a post office packing boxes to mail. Each large box takes 4 feet of packing tape to seal, each medium box takes 2 feet of packing tape to seal, and each small box takes 1 foot of packing tape to seal. Each box also takes 1 foot of packing tape to stick the address label on. Debbie packed two large boxes, eight medium boxes, and five small boxes this afternoon. How much tape did she use?