Answer:

Step-by-step explanation:

Subtracting 4x from both sides of the inequality.

Simplifying the inequality.

The prisoners could do a pattern that could signal who has already been in the room. So for example, one light off, both lights off, one light on, both lights off. But with left and right lights to make the sequence last as long as possible. Then after that sequence to have the last one be the signal that everyone has been in there. I dunno this is tricky lol
13 and 14 becuase 13 being the third largest and 14 being the second largest
Use a porportion to help better and speed up the process