Hello, singh!

At noon, ship A is 125 km east of ship B.

Ship A is sailing west at 35 km/hr, and ship B is sailing north at 35 km/hr.

How fast is the distance between the ships changing at 2:00 P.M.?

I hope you made a sketch . . . Code:

B *
| \
| \
| \
35t | \ x
| \
| \
| \
* - - - - - - - * - - - - - - *
Q 125-35t A 35t P
: - - - - - - 125 - - - - - - :

At noon, ship A is at point P.

In hours, it has moved 35t km to point A.

Then: , and

At noon, ship B is at point Q.

In hours, it has moved 35t km to point B.

Their distance is: .

So we have: .

Can you finish the problem?