Total cost = Price of juice + price of chocolate + tax = 10 + 10 + [(16/100) x 20]
= 20 + 3.2
= $23.2
When you multiply a number by 5 and then by 2 it is the same as multiplying by 10. multiplying by 10 means you add a zero to the end of the number so the digit in the ones column will be always be zero
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
