You are here:

# Basic Math/Mathematics

Question
Two trains leave stations P and Q, 110km apart. Train from P to Q travels at 25Km/hr and train from Q to P at 30Km/hr. If they both start at 8 AM, they meet at:?

d = rt.  the distance for one = d and the other is 110-d, the rate is 25kph and 30kph and the time is equal, so you have 2 equations, d=25(t) and 110-d = 30t.  Since we know that the time is equal, if we solve each equation for t, then we can set them equal to each other and solve.

d=25(t)      110-d = 30t
d/25 = t      (110-d)/30 = t, therefore

d/25 = (110-d)/30  now solve for d
30d = 25(110-d)
30d = 2750 - 25d
55d = 2750
d = 50, so the first train will travel 50 miles while the second train travels 60.  At 25kph and 30kph, it will take 2 hrs before they meet up or, 10AM.
Questioner's Rating
 Rating(1-10) Knowledgeability = 10 Clarity of Response = 10 Politeness = 10 Comment thanks..........

Basic Math

Volunteer

#### Lynn Houston

##### Expertise

I can answer questions in basic algebra and any grade school math.

##### Experience

Love math, currently helping my nephew get through Intermediate Algebra.

Education/Credentials
I majored in Math Ed in college (but decided not to teach), so have over 40 credits of math.