[Question]A farm has 5 less than 9 times the amount of hens as roosters. If there are 75 total chickens, how many hens are there?
[Answer]Let x represent the number of roosters. Number of hens:9x - 5. Total:9x - 5 + x = 75. 10x - 5 = 75. 10x = 80. x = 8. Number of hens: 9(8) - 5 = 67. The answer is 67.
Q: Marcus, Humphrey, and Darrel are bird watching. Marcus sees 7 birds, Humphrey sees 11 birds, and Darrel sees 9 birds. How many birds does each of them see on average?
A: They see 27 total birds because 9 + 11 + 7 = 27. They see an average of 9 birds each because 27 / 3 = 9. The answer is 9.
Question: On Friday, Markeesha sold 30 boxes of crackers for her scout troop's fundraiser. On Saturday, she sold twice as many as on Friday. On Sunday, she sold 15 fewer than Saturday. How many boxes did she sell over the three days?
Answer: On Saturday, she sold 2 * 30 = 60 boxes. On Sunday, she sold 60 - 15 = 45 boxes. She sold a total of 30 + 60 + 45 = 135. The answer is 135.
[Question]The ratio representing the age of Halima, Beckham, and Michelle is 4:3:7, respectively. If the total age for the three siblings is 126, calculate the age difference between Halima and Beckham.
[Answer]The total ratio representing the age of the three siblings is 4 + 3 + 7 = 14. Halima's age is represented by the fraction 4 / 14, which means she is 4 / 14 * 126 = 36 years old. Beckhams age, from the total age of the three, is 3 / 14 * 126 = 27. The difference in age between Halima and Beckham is 36 - 27 = 9. The answer is 9.
Q: To win a brand new Bible at Tom Sawyer's Sunday school, a pupil has to win 10 yellow tickets; each yellow ticket is obtained by trading in 10 red tickets; each red ticket is obtained by trading in 10 blue tickets; and blue tickets are earned by memorizing two Bible verses. But rather than go to all that trouble, Tom Sawyer has traded various toys and treasures of his with his friends until he has gathered 8 yellow, 3 red, and 7 blue tickets. How many more blue tickets would he need to earn to win a new Bible?
A: A red ticket is equal to 10 blue tickets, and a yellow is equal to ten red tickets, so a yellow ticket is also equal to 10 * 10 = 100 blue tickets. It takes 10 yellow tickets to win a Bible, or 10 * 100 = 1000 blue tickets. Tom has 8 yellow tickets, which are worth 8 * 100 = 800 blue tickets. He also has 3 red tickets, which are worth 3 * 10 = 30 blue tickets. Added with his 7 blue tickets, he has 800 + 30 + 7 = 837 blue tickets' worth of tickets. So he still needs to earn 1000 - 837 = 163 blue tickets. The answer is 163.
Question: In 21 hours, a heating plant consumes 7 liters of fuel. How much does it consume in 90 hours?
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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Let x be the consumption in 90 hours. We have: 21 / 7 = 90 / x because the heating plant always consumes fuel at the same rate. Multiplying both sides by 7x, we get 21x = 90 * 7. This can be simplified to 21x = 630. So, the consumption in 90 hours is x = 630 / 21 = 30 liters. The answer is 30.