Answer the following question.
An opera house has 150 rows; each row has ten seats. The ticket costs $10 per show. How much did the opera house earn from one of the shows if 20% of the seats were not taken?
Step-by-step reasoning process: The opera house has 150 x 10 = 1500 seats. There are 1500 x 20 / 100 = 300 seats that were not taken. The total number of seats taken was 1500 - 300 = 1200. Therefore, the opera house earned $10 x 1200 = $12000 from one of the shows.
The answer is 12000.

Answer the following question.
James makes potatoes for a group. Each person eats 1.5 pounds of potatoes. He makes potatoes for 40 people. A 20-pound bag of potatoes costs $5. How much does it cost?
Step-by-step reasoning process: He needs 1.5 * 40 = 60 pounds of potatoes. So he needs to buy 60 / 20 = 3 bags of potatoes. So it cost 3 * 5 = $15.
The answer is 15.

Answer the following question.
Frank has an apple tree in his backyard. 5 apples are hanging on the tree and 8 have fallen to the ground. If Frank's dog eats 3 of the apples off of the ground, how many apples are left?
Step-by-step reasoning process: Frank originally had 5 + 8 = 13 apples. After his dog eats 3, there are 13 - 3 = 10 apples.
The answer is 10.

Answer the following 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?
Step-by-step reasoning process: 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.