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Please help me in my Assignment in Math (10 points is waiting)?
A man rows 16 km upstream and back in 9 hours. He can row 1 km upstream in the same time that he can row 4 km downstream. Find the speed of the boat in still water and the speed of the current.
Representation:
x = rate of boat in still water
y = rate of current
x-y = upstream speed
x+y = downstream speed
Find the Equation and Give Your Solution
1 Answer
- Anonymous1 decade agoFavorite Answer
It's a good one! Here's how I figured it out:
First, we know that the speed formula is like this: v=d/t => t=d/v
+ A man rows 16 km upstream and back in 9 hours. So we have the following equation: x+y=16/9 km/h (1)
+ He can row 1 km upstream in the same time that he can row 4 km downstream. Let's assume that "the same time" is "t". So:
t=t
1/(x-y) = 4/(x+y)
x+y = 4x - 4y <=> 3x-5y=0
From (1) and (2) we calculate and find x=10/9 km/h; y=2/3 km/h
Hope this will help! :D