Betty's daughter is 40 / 100 * 60 = 24 years younger than she is. That means her daughter is 60 - 24 = 36 years old. So the granddaughter is 1 / 3 * 36 = 12 years old.
The answer: 12
Reverse engineering the question: Betty is 60 years old, and she is the oldest person in the family. Her daughter is 40 percent younger than she is, and her granddaughter is one-third her mother's age. How old is the granddaughter?

To make 1 lei, Jaynie will need 2.5 x 12 = 30 plumeria flowers. To make 4 leis, she will need to pick 30 x 4 = 120 plumeria flowers from the trees.
The answer: 120
Reverse engineering the question: Jaynie wants to make leis for the graduation party. It will take 2 and half dozen plumeria flowers to make 1 lei. If she wants to make 4 leis, how many plumeria flowers must she pick from the trees in her yard?

The supplier brought 300 ft - 250 ft = 50 fewer feet of metal roofing. Therefore the total amount of money Mr. Caiden has to pay for the remaining metal roofings is 50 feet * $8 / foot = $400.
The answer: 400
Reverse engineering the question: Mr. Caiden wants to do repairs to his house and requires 300 feet of metal roofing to do this. If each foot of roofing costs $8, and the supplier of the metal roofing brings in 250 feet of metal roofing for free, how much money is Mr. Caiden required to pay for the remaining metal roofing?

First find the total number of pieces of candy Anna gets: 14 pieces / house * 60 houses = 840 pieces. Then find the total number of pieces of candy Billy gets: 11 pieces / house * 75 houses = 825 pieces. Then subtract the number of pieces Billy gets from the number Anna gets to find the difference: 840 pieces - 825 pieces = 15 pieces.
The answer: 15
Reverse engineering the question:
Anna goes trick-or-treating in a subdivision where she gets 14 pieces of candy per house. Her brother Billy goes trick-or-tricking in a neighboring subdivision where he gets 11 pieces of candy per house. If the first subdivision has 60 houses and the second subdivision has 75 houses, how many more pieces of candy does Anna get?