SOLUTION: Here's the problem: Superman and flash are running around the world in opposite directions. Superman can go around the world in 2.5 hours, and Flash can do the same in 1.5 hours.

Question 309263: Here's the problem:
Superman and flash are running around the world in opposite directions. Superman can go around the world in 2.5 hours, and Flash can do the same in 1.5 hours. Assuming they start at the same time and place, how many times will they pass each other going in opposite directions in a 24 hour period?
This is what I know: Distance=rate x time . I made a chart to try to come up with an equation but I am stuck because I am only given the time so I am not sure what to do . help please
Answer by Earlsdon(6294) (Show Source): You can put this solution on YOUR website!
This is Least Common Multiple (LCM) problem.
First find out in how hours they will pass the first time. This number will be the LCM of 1.5 and 2.5
You can write out the multiples of these two numbers as follows:
1.5: 1.5, 3.0, 4.5. 6.0, 7.5, 9.0 ...
2.5: 2.5, 5.0, 7.5, 10.0...
You can see that the LCM is 7.5 which means that they will pass each other every 7.5 hours.
To see how many times they will do this in a 24-hour period, divide 24 by 7.5.

So the answer would be they would pass each other 3 times in a 24-hour period.
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