[Question]There were 200 students on a field playing football. Suddenly a military plane flew by, and 3/4 of the students looked up. How many eyes saw the airplane?
[Answer]If there were 200 students on the field and 3 / 4 of the students looked up at the flying plane, 3 / 4 * 200 = 150 students saw the plane. Since each student has two eyes, the number of eyes that looked at the plane is 2 * 150 = 300 years. The answer is 300.

[Question]If Billy sleeps 6 hours one night, then 2 more hours than that the following night, and then half the previous amount the following night, and then finally triple the previous amount the final night, how much did he sleep in that four day period?
[Answer]Billy slept 6 hours the first night. He then slept 6 + 2 = 8 hours the second night. Billy then slept 8 / 2 = 4 hours the third night. Finally, Billy slept 4 * 3 = 12 hours the fourth night. In total, Billy slept 6 + 8 + 4 + 12 = 30 hours. The answer is 30.

[Question]Erika and her brother Rick want to buy a gift for their mother that costs $250. They have both saved money. Erika saved $155 and her brother saved only half of the cost of the gift. They also want to surprise their mother with a birthday cake that costs $25. How much money will they have left after buying their mother a gift and cake?
[Answer]Rick's savings are half the price of the gift, which is $250 / 2 = $125. The total savings for the two siblings is $155 + $125 = $280. Mom's gift costs $250 + $25 for the cake = $275. Subtracting the total cost of the gift from the total savings, we get $280 - $275 = $5 left. The answer is 5.

[Question]Richard can clean his room in 22 minutes. Cory takes 3 minutes more than Richard to clean her room while Blake can clean his room 4 minutes more quickly than Cory. If they have to clean their rooms twice a week, how many minutes do all three spend cleaning their rooms each week?
[Answer]

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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Cory takes 22 + 3 = 25 minutes to clean her room. Blake takes 25 - 4 = 21 minutes to clean his room. The three of them can clean their room in 22 + 25 + 21 = 68 minutes in all. In a week, they spend 68 x 2 = 136 minutes cleaning their rooms. The answer is 136.