Answer:
It will take 25.2 minutes to complete 21 laps.
Step-by-step explanation:
The rate of covering 5 laps is:
v = 6/5
Therefore, the time taken to cover 21 laps is:
t = 21/v
t = 21*6/5
t = 25.2
Hence, it will take 25.2 minutes or 25 minutes 12 seconds for Lin to complete 21 laps.