Class 10

Math

All topics

Quadratic Equations

A motor-boat takes $2$ hours more to cover a distance of $30km$ upstream than it takes to cover the same distance downstream.If the speed of the stream is $2km/hr$. Find the speed of boat is still water.

Speed upstream $=x−2$

Speed downstream $=x+2$

Time upstream $=x−230 $

Time downstram $=x+230 $

Given:

$x−230 =x+230 +2$

$x−230 −x+230 =2$

$x_{2}−430(x+2−x+2) =2$

$60=x_{2}−4$

$x_{2}=64$

$x=8$