Toy train A crosses a pole after every 24seconds. Toy train B crosses the pole after every 30 seconds and toy train C crosses the pole after every 36 seconds. After how many minutes, do they all cross the pole together?

Answer: 6 minutes

Step-by-step explanation:

From the question, Toy train A crosses a pole after every 24seconds while Toy train B crosses the pole after every 30 seconds and then toy train C crosses the pole after every 36 seconds. We are going to solve this by finding their lowest common multiple (LCM).

24 = 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, 264, 288, 312, 336, 360.

30 = 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 360, 390

36 = 36, 72, 108, 144, 180, 216, 252, 288, 324, 360.

We can see that the lowest common multiple of 24, 30 and 36 is 360.

Since 60 seconds make 1 minute, this will be converted to minutes.

= 360/60

= 6 minutes.

They all cross the pole together after 6 minutes.