MathDB
4 men, different speeds, 1 tunnel, 1 torch, max 2 at a time, min time

Source: Greece JBMO TST 2001 p3

June 17, 2019
combinatoricsalgebraminimum

Problem Statement

44 men stand at the entrance of a dark tunnel. Man AA needs 1010 minutes to pass through the tunnel, man BB needs 55 minutes, man CC needs 22 minutes and man DD needs 11 minute. There is only one torch, that may be used from anyone that passes through the tunnel. Additionaly, at most 22 men can pass through at the same time using the existing torch. Determine the smallest possible time the four men need to reach the exit of the tunnel.