12. Fair attraction In olden days, one could encounter the following attraction at a fair. A light bulb was connected to several switches in such a way that it lighted up only when all the switches were closed. Each switch was controlled by a push button; pressing the button toggled the switch, but there was no way to know the state of the switch. The object was to turn the light bulb on. Design an algorithm to turn on the light bulb with the minimum number of button pushes needed in the worst case for n switches.

Ibelieve the answer is a thermometer.

Jewelers are your best option 

Yeah they want to steal your info and sell it on the dark web. they want your credit/debit card numbers, social security numbers, google passwords, and other stuff. some people install spyware onto your device, which, as the word suggests, is built to spy on your every move, such as what you type. they then sell this information to other people secretly or use it for evil purposes themselves. or both, idk. the reason why this info costs money to learn is because its valuable info. im not saying that i condone it though! hacking sucks, and whoever is involved in it is just a horrible person.