Answer the following question.
Jill can run up a hill at 9 feet/second and down a hill at 12 feet/second. How long does it take her to run up and down a 900 foot hill?
Step-by-step reasoning process: First find the time it takes Jill to run up the hill: 900 feet / 9 feet / second = 100 seconds. Then find the time it takes Jill to run down the hill: 900 feet / 12 feet / second = 75 seconds. Then add the two times to find Jill's total time: 100 seconds + 75 seconds = 175 seconds.
The answer is 175.

Answer the following question.
After Martha went grocery shopping she had 4 bottles of juice in the refrigerator and 4 bottles in the pantry. During the week Martha bought 5 more bottles of juice. If Martha and her family drank 3 bottles of juice during the week, how many bottles are left?
Step-by-step reasoning process: Martha had 4 bottles of juice in the pantry + 4 bottles in the refrigerator = 8 bottles of juice. After Martha went shopping she added 5 bottles of juice to the + 8 bottles she already had = 13 bottles of juice. Martha and her family drank 3 bottles of juice during the week from the 13 they had, 13 - 3 = 10 bottles left.
The answer is 10.

Answer the following question.
Mark hires a singer for 3 hours at $15 an hour. He then tips the singer 20%. How much did he pay?
Step-by-step reasoning process: The cost was 15 * 3 = $45. So the tip was 45 * .2 = $9. So in total, he paid 45 + 9 = $54.
The answer is 54.

Answer the following question.
A school choir needs robes for each of its 30 singers. Currently, the school has only 12 robes so they decided to buy the rest. If each robe costs $2, how much will the school spend?
Step-by-step reasoning process: The school needs to buy 30 - 12 = 18 robes. So the school will spend 18 x $2 = $36.
The answer is 36.