SOLUTION: I NEED HELP ASAP! A motorboat traveled for 2 hous with an 8 KM/H. The return trip against the same current took 3 hours. Find the speed of the motorboat in still water. THANK

Algebra ->  Systems-of-equations -> SOLUTION: I NEED HELP ASAP! A motorboat traveled for 2 hous with an 8 KM/H. The return trip against the same current took 3 hours. Find the speed of the motorboat in still water. THANK      Log On


   

Question 5168: I NEED HELP ASAP!
A motorboat traveled for 2 hous with an 8 KM/H. The return trip against the same current took 3 hours. Find the speed of the motorboat in still water.
THANKS IN ADVANCE
Answer by xcentaur(357) About Me  (Show Source):
You can put this solution on YOUR website!
let speed of the motorboat be x kmph
let speed of current be y kmph


speed with the current=(x+y)=8 km/h
time taken=2 hours
distance=s*t=8*2=16 km


speed against current=(x-y)km/h
distance=16 km
time taken=3 hours
hence,speed=d/t=16/3 hours


x+y=8.......[1]
x-y=16/3....[2]


Adding eqns 1 and 2 we get,
2x=8+16/3
2x=(24+16)/3
2x=40/3
x=(40/3)/2
x=20/3
=6.67 km/h


Hence speed in still water=6.67 km/h