A room has three lightbulbs. each one has a 10% probability of burning out within the month. what is the probability that all three will be lit at the end of the month?

10% chance of burning out

100-10 = 90% chance of not burning out

90% = 0.9

3 lightbulbs

0.9^3 = 0.729 = 72.9%

The probability that all 3 lightbulbs stay lit by the end of the month is 72.9%