42nd Swedish 2002 Problem 2 A, B, C can walk at 5km/hr. They have a car that can accomodate any two of them whch travels at 50km/hr. Can they reach a point 62km away in less than 3 hrs?
Yes. Solution A and B drive a distance 53 km, taking 1.06 hrs. B gets out and walks the remaining 9km on foot, taking 1.80 hrs, so B arrives after 2.86 hrs. Meanwhile C sets out on foot and walks 9.5 km, taking 1.90 hrs. After dropping B, A drives back to arriving 0.87 hrs after dropping B, a total of 1.93 hrs after the start. C has been waiting for 0.03 hrs. A and C then drive to the finish, taking 1.05 hrs, so they arrive 2.95 hrs after the start. 42nd Swedish 2002 © John Scholes jscholes@kalva.demon.co.uk 21 December 2003 Last corrected/updated 21 Dec 03