Question: 1,800 fish swim westward, 3,200 swim eastward, and 500 swim north. What is the number of fish left in the sea, if fishers catch 2/5 of the fish that swam eastward and 3/4 of the fish that swam westward?
Answer: When fishers caught 3 / 4 of the fish that swam westward, their total number reduced by 3 / 4 * 1800 fish = 1350. The total number of fish that remained from the total number that swam eastward is 1800 fish - 1350 fish = 450 fish. If fishers caught 2 / 5 of the fish that swam eastward, their total number reduced by 2 / 5 * 3200 fish = 1280 fish. 3200 fish - 1280 fish = 1920 fish remained in the sea from the number that swam westward. The total number of fish in the sea after fishers caught some is 500 of the number that went north + 450 of the fish that swam westward + 1920 of the fish that swam eastward = 2870 fish. The answer is 2870.

Question: Noemi lost $400 on roulette and $500 on blackjack. How much money did Noemi begin with if she still had $800 in her purse?
Answer: The total amount of money that she lost is $400 + $500 = $900. If she remained with $900, she initially had $900 + $800 = $1700. The answer is 1700.

Question: It takes David 10 minutes to wash 4 windows. David's house has 64 windows. How many minutes will it take David to wash all of the windows?
Answer: It takes 10 minutes to wash 4 windows and he has 64 windows so that breaks down to 64 / 4 = 16 units. It takes 10 minutes to wash a unit of windows and he has 16 units so 10 * 16 = 160 minutes. The answer is 160.

Question: Hannah comes home from work to find her older son taped her younger son to a chair with 22 strands of duct tape. If Hannah can cut 8 strands per minute and her son can cut 3 strands per minute, how long will it take them to free her younger son?
Answer:
First find the total number of strands the two of them can cut per minute: 8 strands + 3 strands = 11 strands. Then divide the total number of strands by the number of strands they cut per minute to find the number of minutes it takes to cut all the strands: 22 strands / 11 strands / minute = 2 minutes. The answer is 2.