1) For a typical citizen the probability of going to the dentist in a one year period is 0.3. Four randomly individuals are interviewed as part of a health care study. Calculate
i) The probability that three OR more individuals have visited the dentist during the past year
I have been trying to solve this question for quite sometime now, but I do not seem to find the correct method for solving it? could somebody please help
2) 10% of a certain type of component are fault. Two components of this type are fitted to a machine, which will function provided at least one of this components is not faulty. Stating the assumptions you make, calculate the probability that the machine will function.
Attempt to answer:
The probability that both components are faulty is 0.1 x 0.1 = 0.01 and therefore the probability that at least one of these components is working is 1-0.01 = 0.99
But then how do I find the probability the machine will work?
I know the formula
P ( M | A ) = P ( M n A) / P(A)
but this doesnt seem to help for this question. How can I solve it?
Thank you very much for any help