CFAT Problem Solving: Time/Rate 2 — Questions and Answers
Question 1: A vehicle travels 240 km in 3 hours. How far will it travel in 5 hours at the same speed?
- 320 km
- 360 km
- 400 km (Correct answer)
- 480 km
Correct answer: 400 km
Speed = 240 ÷ 3 = 80 km/h; distance in 5 h = 80 × 5 = 400 km.
Question 2: Two soldiers start marching toward each other from points 45 km apart, one at 5 km/h and the other at 4 km/h. How long before they meet?
- 4 hours
- 5 hours (Correct answer)
- 4.5 hours
- 9 hours
Correct answer: 5 hours
Combined closing speed = 5 + 4 = 9 km/h; time = 45 ÷ 9 = 5 hours.
Question 3: Pump A fills a tank in 6 hours. Pump B fills the same tank in 3 hours. Working together, how long do they take?
- 4.5 hours
- 2 hours (Correct answer)
- 1.5 hours
- 3 hours
Correct answer: 2 hours
Combined rate = 1/6 + 1/3 = 1/2 tank per hour; time = 1 ÷ (1/2) = 2 hours.
Question 4: A helicopter covers 560 km in 1 hour 45 minutes. What is its speed in km/h?
- 280 km/h
- 300 km/h
- 320 km/h (Correct answer)
- 340 km/h
Correct answer: 320 km/h
1 h 45 min = 1.75 h; speed = 560 ÷ 1.75 = 320 km/h.
Question 5: A train leaves at 08:00 at 90 km/h. A second train leaves the same station at 09:30 on the same track at 120 km/h. At what time does the second train catch the first?
- 12:00
- 13:00
- 14:00 (Correct answer)
- 15:00
Correct answer: 14:00
Head start = 90 × 1.5 = 135 km; closing speed = 30 km/h; catch-up time = 135 ÷ 30 = 4.5 h after 09:30 = 14:00.
Question 6: A runner completes a 10 km race in 50 minutes. What is her average speed in km/h?
- 10 km/h
- 12 km/h (Correct answer)
- 15 km/h
- 20 km/h
Correct answer: 12 km/h
50 min = 5/6 h; speed = 10 ÷ (5/6) = 12 km/h.
Question 7: A convoy travels the first half of a 200 km route at 40 km/h and the second half at 60 km/h. What is the average speed for the whole trip?
- 48 km/h (Correct answer)
- 50 km/h
- 52 km/h
- 55 km/h
Correct answer: 48 km/h
Total time = 100/40 + 100/60 = 2.5 + 1.667 = 25/6 h; avg = 200 ÷ (25/6) = 48 km/h.
CFAT Problem Solving: Time/Rate 2
A vehicle travels 240 km in 3 hours.
How far will it travel in 5 hours at the same speed?