Question

It takes a boat going upstream 11 hours to cover the same distance as it would cover in 9 hours going downstream. What is the speed of the boat if the speed of the current is 2 kilometers per hour?

Answer 1

20

Explanation:

Answer 2

20 km/h

Explanation:

Let b represent the speed of the boat in km/h. Then the distance covered is ...

distance = speed × time

(b -2)(11) = (b +2)(9)

11b -22 = 9b +18 . . eliminate parentheses

2b = 40 . . . . . . . . add 22-9b

b = 20 . . . . . . . . . divide by 2

The speed of the boat is 20 km/h.