A takes 6 hours more than B to cover a distance of 60 km. But if A doubles his speed, he takes 3 hours less than B to cover the same distance. The speed (in km/hr) of A is:

Let speed of A = $$x$$ km/hr and speed of B = $$y$$ km/hr

=> Time taken by B to cover 60 km = $$\frac{60}{y}$$

Thus, time taken by A = $$\frac{60}{x}=6+\frac{60}{y}$$

=> $$\frac{1}{x}-\frac{1}{y}=\frac{1}{10}$$ -----------------(i)

Similarly, $$\frac{60}{2x}+3=\frac{60}{y}$$

=> $$\frac{1}{y}-\frac{1}{2x}=\frac{1}{20}$$ -----------------(ii)

Adding equations (i) and (ii), we get : $$\frac{1}{2x}=\frac{3}{20}$$

=> $$x=\frac{10}{3}=3\frac{1}{3}$$

$$\therefore$$ Speed of A = $$3\frac{1}{3}$$ km/hr

=> Ans - (A)