Question

Jack rides in a motorboat against a river current for 36 km. Then he returns to his
starting point by floating down river on a raft. Tommy travels 9 hours less on the
motorboat than on the raft. Find the speed of the river current if the speed of the
motorboat in still water is 15 km/h.

Answer 1

The speed of the river current is 11.5 km/h.

What is speed?

Speed is the ratio of total distance travelled to total time taken. IT is given by:

Speed = distance / time

Let b represent the speed of the current and t represent the time, hence:

(15 + b)= 36/t

t = 36 / (15 + b)

Also:

(15 - b)= 36/(t + 9)

t = [36 - 9(15 - b)]/(15 - b)

Hence:

36 / (15 + b) = [36 - 9(15 - b)]/(15 - b)

b = 11.5 km/h

The speed of the river current is 11.5 km/h.

Find out more on speed at: https://brainly.com/question/4931057

Answer 2

RSM VERIFIED ANSWER

this answer was written by an RSM student, and has been confirmed by the portal

Answer:

3km/hr

not sure how to do it i just copied off my rsm teacher, but its right lol

also would rly appreciate brainliest but i know i didnt have an explaination. I would also really appreciate if other users would thank and rate this answer so people looking at a later date would know its reliable