A girl goes to her friend's house, which is at a distance of 12 km. She covers half of the distance at a speed of x km/hr. and the remaining distance at a speed of (x+2)km/hr. If she takes 2 hrs 30 minutes to cover the whole distance, find "x" ?
This is simple equation problem.
The velocity for half the distance =
So, Time taken to cross the first half =
The velocity for the other half =
So, Time taken to cross the rest =
So, On with the equation.
Now, Use The Sridhar Acharya's Rule or Quadratic Formula to solve this.
And, Don't forget to check the Discriminant first.
So, Definitely There are two real solutions for
Now first solution for
Now, The second solution for
But speed can't be negative in any circumstances as distance travelled can't be negative.