Example

Example: Finding Travel Time for Pierre and Monique Moving in Opposite Directions

Apply the distance, rate, and time problem-solving strategy to find the unknown travel time when two people depart from the same point and move in opposite directions.

Problem: Pierre and Monique leave their home in Portland at the same time. Pierre drives north on the turnpike at a speed of 7575 miles per hour while Monique drives south at a speed of 6868 miles per hour. How long will it take them to be 429429 miles apart?

  1. Read and draw: Sketch the situation with arrows pointing north (7575 mph) and south (6868 mph), and label the total separation as 429429 miles. Create a rate–time–distance table.
  2. Identify: The travel time until they are 429429 miles apart.
  3. Name: Let tt = the travel time in hours. Multiply each rate by tt to fill in the distance column:
Rate (mph)Time (hrs)Distance (miles)
Pierre7575tt75t75t
Monique6868tt68t68t
429429
  1. Translate: Because they travel in opposite directions from the same starting point, the distance between them is the sum of their individual distances: 75t+68t=42975t + 68t = 429
  2. Solve: Combine like terms: 143t=429143t = 429. Divide both sides by 143143: t=3t = 3.
  3. Check: Pierre's distance: 753=22575 \cdot 3 = 225 miles. Monique's distance: 683=20468 \cdot 3 = 204 miles. Total distance: 225+204=429225 + 204 = 429 miles. \checkmark
  4. Answer: It will take them 33 hours to be 429429 miles apart.

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Updated 2026-04-22

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