Title: Constant Rate of Change PostVideo Questions
Course: Calculus Videos Project Modules

Q: When only half full, an Olympic sized swimming pool holds 330,000 gallons of water. Water is being pumped out of an Olympic pool at a constant rate. Every increase of five minutes in the number of minutes x since half full, the amount of water in the pool decreases by 120 gallons.

Which of the following statements is definitely true? (Note: ∆y can be read as “change in y” and ∆x as “change in x.”)
- ∆x = –24∆y (Incorrect)
- x = –24y (Incorrect)
- y = –24x (Incorrect)
- ∆y = –24∆x (Correct)
- Only statements (a) and (b) are definitely true. (Incorrect)
- Only statements (c) and (d) are definitely true. (Incorrect)
A: ∆y = –24∆x

Q: A candle has been burning at a constant rate of change of 2.25 inches per hour. The candle has been burning for 4 hours and is 4.5 inches tall. What was the length of the candle before it was lit?
- 4.5 inches (Incorrect)
- 6.75 inches (Incorrect)
- 9 inches (Incorrect)
- 13.5 inches (Correct)
- 20.25 inches (Incorrect)
A: 13.5 inches