A boat travels 24 km upstream in 6 hours and 20 km downstream in 4 hours. Then the speed of boat in still water and the speed of current are respectively.

14 kmph and 3 kmph
24.5 kmph and 0.5 kmph
34 kmph and 2 kmph
45 kmph and 2 kmph

Answer:- 1

Explanation:-

Solution:

\begin{aligned} Upstream speed, U \\ = \frac{24}{6} = \frac{12}{3} k m / h \\ Downstream speed , D \\ = \frac{20}{4} = 5 k m / h \\ Speed of boat in still water , x \\ = \frac{D + U}{2} = \frac{9}{2} = 4.5 k m / h \\ Speed of water current, y \\ = \frac{D - U}{2} = \frac{1}{2} = 0.5 k m / h \end{aligned}

$\eqalign{ & {\text{Upstream speed, U}} \cr & {\text{ = }}\frac{{24}}{6} = \frac{{12}}{3}\,km/h \cr & {\text{Downstream speed , D}} \cr & {\text{ = }}\frac{{20}}{4} = 5\,km/h \cr & {\text{Speed of boat in still water , }}x \cr & = \frac{{{\text{D + U}}}}{2} = \frac{9}{2} = 4.5\,km/h \cr & {\text{Speed of water current, }}y \cr & = \frac{{{\text{D - U}}}}{2} = \frac{1}{2} = 0.5\,km/h \cr}$