A boy starts from walking North at a speed of 1.5m/s and a girl starts walking West at the same point, P at the same time at a speed of 2.0m/s. At what rate is the distance between the boy and the girl increasing 6s later?

15m

Step-by-step explanation:

For every second, the boy walks 1.5 m

So 6 x 1.5 m equals 9 m total

For every second, the girl walks 2m

So 6 x 2 m equals 12 m total

The boy walked North, so it would look like he is walking upward

While the girl walking West looks like she is walking to the left

Finding the distance between them would look like solving a right triangle

We're gonna use the Pythagorean theorem

12² + 9² = distance²

144 + 81 = 225

√225 = 15