Friends A and B simultaneously start from P and are moving towards Q, which is 120 km from P. Their speeds are 40 kmph and 60 kmph, respectively. After reaching Q, they immediately return back to P. At what distance from P will A cross B, who is coming from Q to P?

Total distance = 120 km. A's speed = 40, B's speed = 60. B reaches Q (120 km) in 2 hours. A is at 80 km. B turns back. Relative speed = 40 + 60 = 100 kmph. Distance between them = 120 - 80 = 40 km. Time to meet = 40 / 100 = 0.4 hours. Distance from Q where they meet = 60 * 0.4 = 24 km. Distance from P = 120 - 24 = 96 km.