Problema Solution
A boy is at a point A on a straight river. He can row downstream at a rate which is 2 miles an hour faster than he ca run. If he rows downstream to a point B, which is 4 miles below A, and runs, in a direction perpendicular to the river, to a point C, 3 miles from B, it takes him 10 minutes longer than it does to run directly from A to C. How fast can he run?
Answer provided by our tutors
The speed he can run is x
The speed downstream is (x+2)
The equation is
4/(x+2) + 3/x = 5/x + 1/6
(x-4)(x-6)=0
x = 4 or 6
So the speed he can run is 4 mph or 6 mph