Question: At peak hours, 11 am - 1 pm and 5 pm - 6 pm, the local fast-food restaurant serves 12 cars every 15 minutes. Off-peak times, they serve 8 cars every 15 minutes. From 4 pm - 6 pm, how many customers do they serve?
Answer with step-by-step thinking: 5 pm - 6 pm is one hour and they measure service in 15 - minute blocks so 60 / 15 = 4 15 min blocks. At peak times, they serve 12 cars every 15 minutes so they serve 12 * 4 = 48 cars in 60 minutes. Off peak times, 4pm - 5 pm, they serve 8 cars every 15 minutes so they serve 8 * 4 = 32 cars in 60 minutes. From 4pm - 5 pm they serve 32 cars and from 5pm - 6 pm they serve 48 cars so they serve 32 + 48 = 80 cars.
So the answer is 80.

Question: There have been 15 "Where's Waldo?" books published. Each book has 30 puzzles to find Waldo. The average person takes 3 minutes to find Waldo in a puzzle. How long would it take to find every Waldo?
Answer with step-by-step thinking: There have been 450 puzzles because 15 x 30 = 450. It would take 1,350 minutes to find all the Waldo's because 450 x 3 = 1,350.
So the answer is 1350.

Question: Eden's mom is twice as old as Eden, who is twice as old as Devin. If Devin is 12 years old, what's the average age of the three?
Answer with step-by-step thinking:
If Devin is 12 years old, then Eden is 2 * 12 years = 24 years old. Since Eden's mom two times older than Eden, her age is 24 years * 2 = 48 years. In total, they have 48 years + 24 years + 12 years = 84 years. The average age for the three is 84 years / 3 people = 28 years / person.
So the answer is 28.