SOLUTION: The speed of a boat in still water is 10 km/h. The boat travels 12 km upstream and 28 km downstream in a total time of 4 hours. What is the speed of the stream?
Algebra.Com
Question 442916: The speed of a boat in still water is 10 km/h. The boat travels 12 km upstream and 28 km downstream in a total time of 4 hours. What is the speed of the stream?
Answer by jorel1380(3719) (Show Source): You can put this solution on YOUR website!
12/(10-x)+28/(10+x)=4
12(10+x)+28(10-x)=400-4x2
120+12x+280-28x=400-4x2
4x2-16x=0
x2-4x=0
x2=4x
x=4
The speed of the stream is 4 kph..
RELATED QUESTIONS
The current in a stream moves at a speed of 5 km/h. A boat travels 39 km upstream and 39... (answered by Alan3354)
A boat moves 28 km/h in still water. It travels 80 km upstream and 80 km downstream in a... (answered by mananth)
A river is flowing at a rate of 5 km/h. A boat travels 12 km upstream and 10 km... (answered by josgarithmetic)
The speed of a boat in still water is 9 km/h. The boat travels 72 km upstream and 72 km... (answered by ikleyn)
The speed of a stream is 4 km/h. A boat travels 6 km upstream in the same time it takes... (answered by nyc_function)
The current in a stream moves at a speed of 3km/h. A boat travels 40 km upstream and 40... (answered by josmiceli)
The speed of a boat in still water is 8 km/h. It travels 60 km upstream and 60 km... (answered by mananth,ankor@dixie-net.com,Alan3354)
The speed of a stream is 3 km/h. A boat travels 6 km upstream in the same time it takes... (answered by TimothyLamb)
The speed of a boat in still water is 15 km/h. The boat travels 40 km upstream and 40 km... (answered by scott8148)