Problem P. 4025. (December 2007)
P. 4025. A handhold mirror contains a plane mirror on one of its side and a concave mirror of radius of curvature of 30 cm on its other side. You hold the plane mirror 15 cm from your face and notice a spot. By what factor will the image of the spot be enlarged if you turn the mirror, but still keep it at a distance of 15 cm from your face?
Deadline expired on January 11, 2008.
182 students sent a solution. 4 points: Bali-Papp Donát, Balogh Gábor, Hartstein Máté, Hegyi Ádám, Kovács 235 Gábor, Kovács Benjámin, Krämer Zsolt, Lovas Lia Izabella, Marák Károly, Nagy 648 Donát, Ölvedi Tibor, Paripás Viktor, Sós Attila Róbert, Szolnoki Lénárd, Szűcs Gergely, Tóth 123 László, Tóth 222 Barnabás, Varga 777 Ádám, Vécsi Áron, Veres 001 Máté. 3 points: 72 students. 2 points: 86 students. Unfair, not evaluated: 4 solutions.