a person goes a distance of 30 km on his bicycle. the no: of hrs taken by him is 1 hour less than his av.speed in km/hr.find the time taken by him to complete the journey.
let x be the number of hours taken by him.
i.e, 30/x will be his average speed.
by the statement given in the question,
i.e, x2 - x - 30 = 0
by solving the above quadratic equation, we get the roots as 6, -5
-5 cannot be the number of hours hence its discarded.
Therefore, time taken by him to complete his journey is 6 hours