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
Answer:$1.08 cents.
Step-by-step explanation:
$6 - $4.52 = $1.08.
Faucet one fills up

of the bathtub in one minute and faucet two fills up

of the bathtub in one minute. If both are one then they will fill up

So, 1/6 of the bathtub in one minute.