Cindy gave her four friends 80 marbles each, a total of 4 * 80 = 320 marbles. She was left with 500 - 320 = 180 marbles. Four times the number of marbles she has remaining is 180 * 4 = 720.
The answer: 720
Reverse engineering the question: Out of the 500 marbles that Cindy had, she gave her four friends 80 marbles each. What's four times the number of marbles she has remaining?

Each bag of oranges weighs 24 pounds / 12 = 2 pounds. 8 bags of oranges would weigh 8 * 2 pounds = 16 pounds.
The answer: 16
Reverse engineering the question: If 12 bags of oranges weigh 24 pounds, how much do 8 bags weigh?

The pebble's total splash width is 1.5 meters because 6 times 1 / 4 equals 1.5. The rock's total splash width is 1.5 meters because 3 times 1 / 2 equals 1.5. The boulder's total splash width is 4 because 2 times 2 equals four. The total splash width for all the rocks is 7 because 1.5 plus 1.5 plus 4 equals 7.
The answer: 7
Reverse engineering the question: TreQuan is throwing rocks in the river and he notices that the bigger the rock, the wider the splash. Pebbles make a splash that is a 1/4 meter wide. Rocks make a splash that is 1/2 a meter wide, and boulders create a splash that is 2 meters wide. If he tosses 6 pebbles, 3 rocks, and 2 boulders, what is the total width of the splashes he makes?

Because it is cheaper to buy the packs of 5, the teacher should satisfy the 11 students who want the vampire theme with 2 packs of 5 and 1 individual bag. This will cost the teacher 2 * 3 + 1 * 1 = $7. Similarly, the 14 students who want a pumpkin - themed bag can be satisfied by 2 packs of 5 and 4 individual bags at a cost of 2 * 3 + 4 * 1 = $10. Therefore, the teacher must spend 7 + 10 = $17.
The answer: 17
Reverse engineering the question:
An elementary school teacher is making Halloween goodie bags for her class. She wants the bags to be personalized, so she surveys her students asking whether they'd like a vampire-themed bag or a pumpkin-themed bag. Of her 25 students, 11 indicate they want the vampire-themed bag and 14 indicate they want the pumpkin-themed bag. The store the teacher shops at sells packs of 5 of each theme at a price of $3 per package, as well as individual bags of each theme at a price of $1 each. What is the least amount of money the teacher can spend on the bags if she buys every student the theme they requested?