Problem 5 · 2026 AMC 8
Stretch
Ratios, Rates & Proportions
distance-speed-time
Casey went on a road trip that covered 100 miles, stopping only for a lunch break along the way. The trip took 3 hours in total and her average speed while driving was 40 miles per hour. In minutes, how long was the lunch break?
Show answer
Answer: B — 30 minutes.
Show hints
Hint 1 of 2
The 40 mph only describes the part where she's actually moving — the 3 hours also hides the lunch stop. Which piece can you compute directly?
Still stuck? Show hint 2 →
Hint 2 of 2
Time = distance ÷ speed gives the driving time only. Subtract that from the 3 total hours and what's left is the break.
Show solution
Approach: the 3 hours is driving + break; only driving obeys distance ÷ speed
- The 40 mph is her speed while driving, so distance ÷ speed gives only the driving time, not the whole trip. Find that first: 100 ÷ 40 = 2.5 hours.
- Whatever's left of the 3 total hours is the lunch break: 3 − 2.5 = 0.5 hour = 30 minutes.
- Sanity check: 30 minutes of lunch is reasonable, and 2.5 h of driving at 40 mph really does cover 100 miles. The reusable idea: always separate ‘moving time’ from total time before using rate = distance ÷ time — the rate only describes the moving part.
Mark:
· log in to save