Erica and Amy started biking in the opposite directions at the same time from the same place. Erica biked at a speed of 6 meters per second and Amy biked at a speed of 4 meters per second. How soon were they exactly 1 km apart? Answer: minute (s) and second (s)

Step-by-step explanation:

1km = 1000 meters

Let t represent the time it will take them to be 1km (1000 meters) apart.

Distance = speed * time

Erica biked at a speed of 6 meters per second. This means that the distance that Erica travelled in t seconds would be 6t.

Amy biked at a speed of 4 meters per second. This means that the distance that Amy travelled in t seconds would be 4t.

Since the total distance covered after t seconds is 1km (1000 meters), it means that

6t + 4t = 1000

10t = 1000

t = 1000/10

t = 100 seconds

The number of seconds in a minute is 60

Converting to minutes and seconds, it becomes

1 minute, 40 seconds