It has been found that 80% of all printers used operate correctly at the time of installation. A seller sells 10 units during a month.

1)find the prob.that at least 9 of the printers operate correctly at the time of installation.

2)Consider 5 months in which 10 units are sold per month. What is the prob.that at least 9 units operate correctly in each of the 5 months

For 1st part :
Let p(o)=probability that a given printers operates correctly

So we have to find p(o>=9) here.

How to apply the value 80% in this one and solve this question?

1 answer

I guess I was able to sort the question out using binomial distribution