Mathematical and Physical Journal
for High Schools
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Problem P. 3834. (November 2005)

P. 3834. Electric toothbrushes are becoming more and more popular. Calculate the cost of operating one during a year if it dissipates a power of 2 W, and each day you spend 4 minutes cleaning your teeth. The price of 1 kWh electric energy is 34 forints.

(3 pont)

Deadline expired on December 12, 2005.


345 students sent a solution.
3 points:302 students.
2 points:13 students.
1 point:21 students.
0 point:1 student.
Unfair, not evaluated:8 solutions.

Problems in Physics of KöMaL, November 2005