Answer:
See explanation below
Step-by-step explanation:
Lap 1 + Lap 2 + Lap 3 = 1 min 43 seconds
Lap 2 + Lap 3 = timed by coach
Hence,
Lap 1 + "timed by coach" = 1 min 43 seconds
Lap 1 = 1 min 43 seconds - "timed by coach".
So, Kelly can subtract the time taken on last 2 laps (from coach) from 1 minutes and 43 seconds