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43 votes
43 votes
NEED EXPLANATION TOO! THANKS BESTIES

There are 3 different trains running to London. One train
leaves every 10 minutes, another leaves every 35 minutes,
and the last one leaves every 40 minutes. They first leave at
5:30am. What Time do they all leave again at the same time?

User Fumisky Wells
by
2.7k points

1 Answer

21 votes
21 votes

Answer:

2:50pm

Explanation:

You have to find the least common multiple (LCM) between the 3 times. If you don't know what is the LCM, just say it and I'll try to explain for you in the comments.

10, 35, 40 have as LCM the number 560

So it means they'll leave together 560 minutes after 5:30am

One hour is 60 minutes, so we can divide 560 by 60 to find the time in hours:

560/60 = 9 hours and 20 minutes (the rest of the division will be the minutes)

So, they'll leave together at 2:50pm

User Marco Boschi
by
2.9k points