Math Problem Statement

A train leaves station A at 5am and reaches station B at 9am on the same day. Another train leaves station B at 7am on the same day and reaches station A at 10:30am . So what time will both trains meet?

Solution

To determine the time when both trains meet, we can follow these steps:

1. Determine the total time taken by each train for its journey:

  • Train 1 (leaves station A at 5:00 AM and reaches station B at 9:00 AM):

    • Time taken = 9:00 AM - 5:00 AM = 4 hours.
  • Train 2 (leaves station B at 7:00 AM and reaches station A at 10:30 AM):

    • Time taken = 10:30 AM - 7:00 AM = 3.5 hours.

2. Calculate the relative positions of both trains when Train 2 departs:

At 7:00 AM (when Train 2 departs), Train 1 has been traveling for 2 hours (since it started at 5:00 AM). Since Train 1 takes 4 hours to complete the journey, it has covered half the distance (2 hours out of 4 hours).

3. Calculate the speed ratios of the trains:

Since both trains are traveling toward each other, we need to consider their relative speeds. Let's assume that the distance between Station A and Station B is DD.

  • Speed of Train 1 = D4\frac{D}{4} (distance covered per hour).
  • Speed of Train 2 = D3.5\frac{D}{3.5}.

4. Set up the equation for the meeting time:

Let the time after 7:00 AM when both trains meet be tt hours. In that time:

  • Train 1 will cover a distance of D4×t\frac{D}{4} \times t,
  • Train 2 will cover a distance of D3.5×t\frac{D}{3.5} \times t.

Since Train 1 had already covered half the distance before 7:00 AM, the remaining distance is D2\frac{D}{2}. Therefore, the sum of the distances covered by both trains should equal D2\frac{D}{2}:

D4×t+D3.5×t=D2\frac{D}{4} \times t + \frac{D}{3.5} \times t = \frac{D}{2}

5. Solve for tt:

Dividing the entire equation by DD:

t4+t3.5=12\frac{t}{4} + \frac{t}{3.5} = \frac{1}{2}

To simplify the fractions, we convert 3.5 to 72\frac{7}{2}:

t4+2t7=12\frac{t}{4} + \frac{2t}{7} = \frac{1}{2}

Find the least common denominator (28) and rewrite the equation:

7t28+8t28=1428\frac{7t}{28} + \frac{8t}{28} = \frac{14}{28}

Simplifying:

15t28=1428\frac{15t}{28} = \frac{14}{28}

Multiply both sides by 28:

15t=1415t = 14

Solve for tt:

t=1415 hours0.933 hours.t = \frac{14}{15} \text{ hours} \approx 0.933 \text{ hours}.

This is approximately 56 minutes.

6. Determine the time:

Since both trains meet 56 minutes after 7:00 AM, they will meet at:

7:00AM+0:56minutes=7:56AM.7:00 \, \text{AM} + 0:56 \, \text{minutes} = 7:56 \, \text{AM}.

Answer: The two trains will meet at 7:56 AM.


Would you like any further details, or have any questions?

Here are 5 related questions to expand your understanding:

  1. How would the meeting time change if Train 2 started earlier?
  2. What if Train 1 had a different travel time, say 5 hours instead of 4?
  3. How can we calculate the distance between the stations if we knew the speeds of the trains?
  4. What would happen if both trains started at the same time but from different stations?
  5. How would the solution change if the trains were moving at constant but different accelerations?

Tip: When solving problems with relative motion, focus on the combined speed or distance between the objects moving towards or away from each other.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Relative Motion
Speed-Time Calculations
Distance-Time Relationships

Formulas

Speed = Distance / Time
Relative Distance = Distance covered by Train 1 + Distance covered by Train 2
Time to meet = Remaining distance / Combined speed

Theorems

Relative Speed Theorem

Suitable Grade Level

Grades 8-10