
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A and B move at a constant speed along a circular track with a circumference of 400 meters. A completes one lap in 4 minutes, while B takes 7 minutes to complete one lap. They start simultaneously from the same point and move in the same direction. After A completes 10 laps, A reverses direction. Whenever A catches up with B or meets B head-on, they clap their hands. How much time has passed for A when they clap their hands for the 15th time? How far has B traveled in that time?

Present the answer in LaTex format: \boxed{Your answer}
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