A person has to cover a distance of 91 km. If he increases his speed by 6 km/hr he reaches 6 hour early. Find his initial speed (in km/hr).

5 7 11 9

7

Let the initial speed = x km/hr ATQ, \(\frac{91}{x}-\frac{91}{x+6}=6\) let x = 7 (by using option) \(\frac{91}{7}-\frac{91 }{13}=6\) 13 – 7 = 6 (satisfied) so, x = 7