⚡ Build the skills to land top-paying quant jobs. Offer ends in --d --h --m --s-- days -- hours -- minutes -- seconds.
⚡ Build the skills to land top-paying quant jobs. Offer ends in 19d 08h 35m 36s19 days 8 hours 35 minutes 36 seconds.
There is an ordinary incandescent light bulb inside a room and four switches outside. You cannot see the bulb from outside the room. All switches are currently at off state and only one switch controls the light bulb. You may turn any number of switches on or off any number of times you want, and you may wait as long as you like, but once you are inside the room you cannot operate the switches. What is the minimum number of times you need to go into the room to figure out which switch controls the light bulb?