So many lights
In a hall in a school there are 100 light bulbs labelled from 1 to 100 and their switches are also numbered accordingly.100 students enter the hall one by one.each student operates the switch(es) whose number is a multiple of his order of entering the hall.provided all switches were initially off,how many bulbs will be on after all students have entered?
For example: The student who enters at number 1 will on all the switches.student no.2 will off switches with no. 2,4,6,8......98,100.and so on.
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1 solution
Actually you just hinted the answer by saying the first person who entered will turn on every lights (even without so, the first person will turn every of them on as they are turning the light in multiple of 1).
ps. Please do NOT write the question with all CAPS.