Question

There are 100 parts. Five of them are out of the specification and others meet the

specification. Randomly select parts from this lot, one by one, without replacement, until an

out-of-specification part is selected.

Let N denote out-of-specification part and S denote part that meets specification.

What is the sample space?

explain in details please, I dont understand

Answer 1

There are 100 parts.

5 are out of specification, and other 95 parts meet the specification.

N denotes the out of specification parts.

S denotes the parts that meet specification.

We randomly select parts from this lot, one by one, until an out of specification part is selected.

Now, this means we keep drawing until we get an N. If we get S, we again draw.

So, the sample space can be

I get my first N in the first draw.

I get my first N in the second draw.

I get my first N in the third draw.

.

.

.

.

Similarly,

I get my first N in the 96th draw.

This is because I can draw S maximum of 95 times; there are 95 S's.

So, the sample space is