Help me with this question, with full explanation

Probability formula is

number of favorable outcomes/ total number of outcomes.

It is given bit I just want to give a working exprencje.

So we get 200 days.

Which is the total number of outcomes,

A. We must find the number of outcomes that gives us 0 defective parts.

There is 50 of them so

P( 0 defective parts) is

or

1/4

B. At least one defective part, is the complement to zero defective part. If we find the probability of the something have zero parts, etc, that is the component to something thar has at least one.

Probability for complement is

This case, p^c is the probability of at least one and p(e) is probability of zero defective parts,

So the probability is 0.75 or 3/4

C. Let find probability of items over 5 defective parts,

So the probability is

or

0.27