Question

Two boat landings are 2.7 km apart on the
same bank of a stream that flows at 3.5 km/hr.
A motorboat makes the round trip between
the two landings in 2.9 hr.
What is the speed of the boat relative to
the water?

Answer 1

help

Answer 2

ayee

Answer 3

t1 + t2 = total time
d/V1 =t 1
d/V2 =t2

d/V1 +d/V2 = total time
2.7 /(V-3.5) + 2.7/(V+3.5) = 2.9
\[ \frac{(V+3.5) + (V-3.5) }{ (V+3.5) (V-3.5) } = \frac{ 2.9 }{ 2.7 }\]

\[{(V+3.5) + (V-3.5) } = \frac{ 2.9 }{ 2.7 } (V+3.5) (V-3.5)\]

expand and group like terms. solve the quadratic for V