posted by .

One model train travels around a loop every 5 minutes. The other travels on anothe loop every 4 minutes. If they begin at the same point at the same time, how much time will pass before they meet at that point again?

  • Math -

    The rate for the first is one loop per 5min, the other one loop per four minutes. The combined rate is the sum of these:

    1loop= (lloop/5min + 1loop/4min)*time

    time= 1/(1/5 + 1/4) minutes

    This is somewhat tricky to get combined, if you wish, you can make decimas..

    time= 1/(.2+.25)= 1/.45 and you take it from there.

  • Math -

    200,000=?thousands ? ten thousands ? hundred thousands

  • Math -

    time= 1/.45= 2.2 seconds.

  • Math -

    oops..time= 2.2 minutes.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    Two trains, each having a speed of 30 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 60 km apart and heads directly for the other train. On reaching …
  2. Math

    Hello, I have trouble doing this problem: Sarah can bicycle a loop around the north part of Lake Washington in 2 hours and 40 minutes. If she could increase her average speed by 1km/hr, it would reduce her time around the loop by 6 …
  3. 4th grade

    trains begin to stop at terminal b every morning at 5 a.m. and then come every 20 minutes for the next 3 hours. mr success needs 15 minutes to get to terminal b from his house. .if mr. success leaves his house at 7:08 a.m., what is …
  4. Math

    kelly, angela, pam riding bikes around 3 mile loop. it takes kelly 15 minutes to complete a loop. it takes angela 18 minutes to complete loop. it takes pam 20 minutes to complete a loop. in how many minutes will kelly and angela arrive …

    A roller coaster cart with a mass of 13 kg travels around two frictionless, circular loops. It just barely makes it around the top of the first circular loop which has a radius of 24 meters. It then travels around the other loop with …
  6. maths

    the ghaziabad train passes every 20 minutes the faridabad train passses every 15 minutes the gurugaon train passes every 18 minutes it is 6 p m and all the train just passed by when is the next time that will happen
  7. Physics

    In the figure below, a small block of mass m = 0.034 kg can slide along the frictionless loop-the-loop, with loop radius 8 cm. The block is released from rest at point P, at height h = 7R above the bottom of the loop. (For all parts, …
  8. Math

    Alvin, Calvin and Melvin are running laps around a track. Alvin runs a lap every 4 minutes, Calvin runs a lap every 6 minutes and Melvin runs a lap every 9 minutes. If they start off at the same point, how many minutes will it take …
  9. algebra (motion)

    Runners A and B practice in a round track going in opposite directions. Runner A takes 40 minutes to go once around the track. The two begin at the same time and meet every 15 minutes. How long does B take to go once around the track?
  10. Math

    Two trains leave the same station at the same time, but are headed in opposite directions. One train travels at 70 mph and the other train travels at 80 mph. How much times passes until the trains are 600 mi apart?

More Similar Questions