Christopher has 64 quarters so he has 64 * .25 = $16.00. Karen has 32 quarters so she has 32 * .25 = $8.00. If Christopher has $16.00 and Karen has $8.00 then Christopher has 16 - 8 = $8.00 more than Karen.
The answer: 8
Reverse engineering the question: Karen has 32 quarters in her piggy bank. Her older brother Christopher has 64 quarters in his piggy bank. How much more money does Christopher have?
Reasoning and answer: He burns 2 * 300 = 600 calories an hour. He dances for .5 * 2 = 1 hour per day. So he burns 600 * 1 = 600 calories per day. So he burns 600 * 4 = 2400 calories per week.
The answer: 2400
What was the question?
Question: James takes up dancing for fitness. He loses twice as many calories per hour as he did when he was walking. He dances twice a day for .5 hours each time and he does this 4 times a week. He burned 300 calories an hour walking. How many calories does he lose a week from dancing?
The total cost of renting the cottage for 8 hours is $5 x 8 = $40. So, each friend pay $40 / 2 = $20 each.
The answer: 20
Reverse engineering the question: Jack and Jill shared the cost of renting a cottage that costs $5 an hour. If they rented it for eight hours, how much did each friend pay?
Reasoning and answer: One less than 5 is 5 - 1 = 4. If one tarantula egg sac can contain 1000 tarantulas, then four egg sacs can hold 4 * 1000 = 4000 tarantula babies. If each tarantula baby has eight legs, the 4 egg sacs can contain 4000 * 8 = 32,000 baby tarantula legs.
The answer: 32000
What was the question?
Question: If a tarantula has eight legs, and one tarantula egg sac can contain 1000 tarantulas, how many baby tarantula legs would be in one less than 5 egg sacs?
Nina made 2 cake layers which were equal to 2 x 12 = 24 cupcakes. She made the equivalent of 24 + 12 = 36 cupcakes in all. Thus, there are 720 / 36 = 20 grams of sugar in a cupcake.
The answer: 20
Reverse engineering the question: Nina made a two-layer cake and a dozen cupcakes for her friend's birthday party. Each layer of cake takes the same amount of sugar to make as a dozen cupcakes. Nina used 720 grams of sugar to bake everything. How many grams of sugar are in one cupcake?
On their first day to the grand canyon, the family took half as many photos as the ones they have in the gallery, meaning they took 1 / 2 * 400 = 200 photos. The total number of photos if they add the ones they took on the first day to the family's gallery is 400 + 200 = 600. On the second day, they took 120 more photos than they took on the first day, a total of 200 + 120 = 320 photos. After adding the photos they took on the second day to the galley, the number of photos will be 600 + 320 = 920.
The answer: 920
Reverse engineering the question:
Lilah's family gallery has 400 photos. On a two-day trip to the Grand Canyon, they took half as many photos they have in the family's gallery on the first day and 120 more photos than they took on the first day on the second day. If they added all these photos to the family gallery, calculate the total number of photos in the gallery.