SOLUTION: There are 3 different trains. One train leaves every 15 min, the other leaves every 20min and the last one leaves every 45 min. They all leave at 6:15 what time do they leave again

Question 1034969: There are 3 different trains. One train leaves every 15 min, the other leaves every 20min and the last one leaves every 45 min. They all leave at 6:15 what time do they leave again at the same time
Answer by fractalier(6550) (Show Source): You can put this solution on YOUR website!
This is asking you to find the first common multiple of 15, 20 and 45.
You can do this by listing their multiples or by finding their prime factorizations...without having to show you that second method, let's list 'em:
15,30,45,60,75,90,105,120,135,150,165,180
20,40,60,80,100,120,140,160,180
45,90,135,180
You can see that the first number that is on all three lists is 180 minutes.
So 180 minutes after 6:15 is 9:15.
By the way,

RELATED QUESTIONS
Train a leaves the station every 10 min and train b leaves the station every 15 min. IF... (answered by richwmiller)

every 15 min. the fast train arrives & waits 4 min. Then 4 min. after the fast train... (answered by stanbon,solver91311)

THERE ARE TWO TRAINS THAT LEAVE FROM THE STAMFORD TRAIN STATION ON MONDAY MORNINGS. THE A (answered by josmiceli)

a train runs every 40 minutes between two towns. if the first train leaves at 7: 45 what... (answered by ewatrrr)

There are two trains coming from opposite directions One leaves at 8:45 The other... (answered by ikleyn)

one train leaves the station at 12:00pm. The other train traveling at 12mph slower leaves (answered by jorel555)

If A train leaves the station every 12 minutes. If B train leaves the station every 9... (answered by rfer)

One bus leaves a stop every 9 min. a 2nd bus leaves every 15 min. if they both left at... (answered by richwmiller)

There are two trains. One train leaves at 5:00 PM From Chicago and is traveling at 50... (answered by jorel1380)