Question

A boat traveled 150 miles downstream (with the current) and back (against the current). The trip downstream took 10 hours. The trip back took 30 hours. What is the speed of the boat (b) in still water? What is the speed of the current (c)?

Answer 1

b= 10 miles/hr and c= 5 miles/hr

Explanation:

Let it's downstream and upstream speed be d and u respectively

also speed of the boat be b and speed of stream be c.

as per question d = 150/10= 15 miles/hr

and, u= 150/30= 5 miles/hr

also we know d= b+c = 15.....i and u = b-c= 5....ii

solving i and ii we get b= 10 miles/hr and c= 5 miles/hr