Answer:
The 3 will complete a lap around the neighborhood in 60 seconds ( 1 minute)
Step-by-step explanation:
The time each of the three can take is 15 , 20, 30 seconds
Now, we want to calculate the time at which all 3 will complete a lap around the neighborhood at the same time
To calculate this, we simply look for the lowest common multiple of the three numbers
The lowest common multiple of 15, 20 and 30 seconds is 60 seconds ( 1 minute)
