Problem P. 3975. (April 2007)
P. 3975. There are switches at both ends of a long corridor. The lamp in the middle of the corridor can be turned off or on with both switches.
a) Draw the circuit.
b) What fraction of the time is the lamp on if one of the switches is turned at every 2 minutes and the other is switched in every three minutes.
Deadline expired on May 11, 2007.
116 students sent a solution. 4 points: 72 students. 3 points: 18 students. 2 points: 9 students. 1 point: 2 students. 0 point: 5 students. Unfair, not evaluated: 10 solutions.