P and Q are two points on a highway, 300 km apart. Two bikers A and B start at the same time from P towards Q. The speed of B is 12 km/h less than that of A. On reaching point Q, biker A immediately returns towards P. He meets B on the road at a place 60 km away from Q. What is the speed of A?

The distance between P and Q is 300 km. Biker A travels from P to Q (300 km) and then returns 60 km towards P to meet B, covering a total distance of 360 km. Biker B, starting at the same time, travels from P towards Q and meets A at a point 60 km away from Q, meaning B has covered 300 - 60 = 240 km. Since they start and meet at the same time, the ratio of their speeds is equal to the ratio of their distances: Speed(A)/Speed(B) = 360/240 = 3/2. Let Speed(A) be 'x' and Speed(B) be 'x - 12'. Setting up the ratio: x / (x - 12) = 3/2. Solving for x: 2x = 3x - 36, which gives x = 36 km/h. Thus, the speed of A is 36 km/h.