Question: Wild Bill can shoot a pistol while riding his horse at full speed. His horse runs at 20 feet per second, and a bullet fired from his gun flies at a speed of 400 feet per second. But if he fires a gun while riding his horse, and the gun is aimed in the same direction that the horse is running, how much faster, in feet per second, is the bullet flying than if he fires the bullet in the opposite direction of what the horse was running?
Answer: If he fires a bullet in the same direction as the direction that the horse is running, the total speed of the bullet is the sum of the speed the bullet was propelled out of the gun plus the speed of the horse, for a combined speed of 400 + 20 = 420 feet per second. If he fires a bullet in the opposite direction as the direction in which the horse is running, then the total speed of the bullet is the speed the bullet was propelled out of the gun minus the speed of the horse, for a resulting speed of 400 - 20 = 380 feet per second. Thus, when firing the gun in the same direction as the horse is running, the bullet moves at 420 - 380 = 40 feet per second faster than when he fires the bullet in the opposite direction as what the horse is running. The answer is 40.

Question: Jerry works five days a week as a waiter and earns a variable amount of tips every night. The past four nights, he earned $20, $60, $15, and $40. How much does he need to earn tonight if he wants to make an average of $50 in tips per night?
Answer: The total money Jerry needs to make for 5 days to get $50 per night is 5 nights * $50 / night = $250. His total earnings for the past four days is $20 + $60 + $15 + $40 = $135. So, Jerry needs to earn $250 - $135 = $115 in tips tonight. The answer is 115.

Question: A group of 4 fruit baskets contains 9 apples, 15 oranges, and 14 bananas in the first three baskets and 2 less of each fruit in the fourth basket. How many fruits are there?
Answer: For the first three baskets, the number of apples and oranges in one basket is 9 + 15 = 24. In total, together with bananas, the number of fruits in one basket is 24 + 14 = 38 for the first three baskets. Since there are three baskets each having 38 fruits, there are 3 * 38 = 114 fruits in the first three baskets. The number of apples in the fourth basket is 9 - 2 = 7. There are also 15 - 2 = 13 oranges in the fourth basket. The combined number of oranges and apples in the fourth basket is 13 + 7 = 20. The fourth basket also contains 14 - 2 = 12 bananas. In total, the fourth basket has 20 + 12 = 32 fruits. The four baskets together have 32 + 114 = 146 fruits. The answer is 146.

Question: My brother and I have thirty minutes to go to school, without being late. It takes us 15 minutes to arrive at the school gate, and another 6 minutes to get to the school building. How much time do we have to get to our room, without being late?
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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The total time we spent going to school is 15 minutes + 6 minutes = 21 minutes. We have 30 minutes - 21 minutes = 9 minutes left not to be late. The answer is 9.