Let s be the number of still lifes Bethany saw and p be the number of portraits. We know that s + p = 80 and s = 4p. Substituting the second equation into the first equation, we get 4p + p = 80. Combining like terms, we get 5p = 80. Dividing both sides by 5, we get p = 16.
The answer: 16
Reverse engineering the question: At the museum, Bethany saw 4 times more still lifes than portraits. If she saw 80 paintings total, how many portraits did she see?


Reasoning and answer: Two bracelets need 50 x 2 = 100 beads. So they will need 9 x 100 = 900 beads in all.
The answer: 900
What was the question?
Question: Nine members of the crafts club are making 2 necklaces each. It takes 50 beads to make each necklace. How many beads will they need in all?


Theon's estimated time of arrival is 90 / 15 = 6 hours. Yara's estimated time of arrival is 90 / 30 = 3 hours. Therefore, Yara is ahead by 6 - 3 = 3 hours.
The answer: 3
Reverse engineering the question: Theon's ship can move 15 nautical miles per hour while Yara's ship can move 30 nautical miles per hour. If their destination is 90 nautical miles away, how many hours ahead will Yara be ahead of Theon?


Reasoning and answer: Johnny spends 6 / 3 = 2 hours walking the 6 dogs who have 60 - minute walks. He makes $20 * 6 = $120 for these walks. Thus, he has 4 - 2 = 2 hours = 120 minutes left to walk the other dogs. He can walk 3 * (120 / 30) = 12 dogs in this time. Thus, he will make $15 * 12 = $180 on these walks. In total per day, he makes $120 + $180 = $300 per day. Thus, during the week, he makes $300 * 5 = $1500.
The answer: 1500
What was the question?
Question: Johnny is a dog walker. He can walk 3 dogs at once. He gets paid $15 for a 30-minute walk and $20 for a 60-minute walk. Johnny works for 4 hours per day. If he always walks the maximum number of dogs possible and 6 dogs have 60-minute walks per day, how much money does he make in a week where he works 5 days?


500 grams is 0.5 kilogram, so for the meat, Martha needs to pay 0.5 * 8 = $4. For the cheese, Martha needs to pay 1.5 * 6 = $9. So in total for the ingredients, Martha needs to pay 4 + 9 = $13.
The answer: 13
Reverse engineering the question: To make a lasagna Martha needs 1.5kg of cheese and 500 grams of meat. The cheese costs $6 per kilogram, and the meat $8 per kilogram. How much does Martha need to pay for the ingredients?


Each run will hold 7 * 2 = 14 people. The ride will have to run 84 / 14 = 6 times.
The answer: 6
Reverse engineering the question:
There are 84 people waiting in line to ride a roller coaster at an amusement park.  The roller coaster has 7 cars, and each car seats 2 people.  How many times will the ride operator have to run the roller coaster to give everyone in line a turn?