CHAPTER 9 / SPECIAL MATH PROBLEMS 347
For each of the following rates, write the formula of the rate and the corresponding “rate pyramid.”
- Speed is miles per hour.
- Efficiency is miles per gallon of fuel.
- Typing speed is pages per minute.
Find the missing quantity, including the units, in each of these rate situations.
- A train travels for 375 miles at 75 mph.
- A car that gets 28 miles per gallon uses 4.5 gallons of fuel.
- Harold can type 600 words in 5 minutes.
- A landscaper who cuts 1.6 acres of grass per hour cuts an 8-acre lot.
- A train leaves New York at 1:00 pm, going 50 mph, bound for Philadelphia, which is 90 miles away. If it
makes no stops, at what time should it be expected to arrive? - Anne can paint a room in 2 hours, and Barbara can paint a room in 3 hours. When they work together, their
work rate is the sum of their rates working separately. How long should it take them to paint a room if they
work together?
Concept Review 4: Rate Problems