Question

Lightbulbs i. a room has three lightbulbs. each one has a 10% probability of burning out within the month. the next exercise refers to this. what is the probability that at the end of the month at least one of the bulbs will be lit? write the probability as a percentage. (fill in the blank below and round your answer to 1 decimal place.) the probability that at the end of the month at least one of the bulbs will be lit is 0.1 %.

Answer 1

The probability that at least one will be lit is 99.9%.

To find the probability that at least one is lit we start with the probability that they all burn out:

(0.1)(0.1)(0.1) = 0.001

The probability that one or more of them is lit is 1-(the probability none are lit):
1 - 0.001 = 0.999 = 99.9%