Question

If you can’t answer seriously then don’t answer at all

A number is selected randomly from a container containing all integers from 10 to 50. Find P(greater than 30leven). Enter your answer in decimal form rounded to two decimal places.

Answer 1

The container has a total of 41 possible numbers from which to draw, and so each one as a probability of
`\frac1{41}` of being drawn.

Most of these numbers are even (21 of them) and

`P(\text{even})=(21)/(41)`

20 of these numbers are greater than 30, so

`P(\text{greater than 30})=(20)/(41)`

and among these, exactly half are even, so that

`P(\text{greater than 30 AND even})=(10)/(41)`

So we have

`P(\text{greater than 30}\mid\text{even})=\frac{P(\text{greater than 30 AND even})}{P(\text{even})}=((10)/(41))/((21)/(41))=(10)/(21)\approx0.48`