Question

If 1 in 5 vehicles are green, and I have 5 vehicles, what is the probability of me having a green vehicle?

Answer 1

In cases like this it is better to compute the chance that you have no green verhicle at all.

Explanation:

It's like throwing a five-sided dye.
The probability for your first vehicle to be not-green is `4/5`

This goes for all five, so the total probability of all vehicles to be not-green (this is an AND-question, so you MULTIPLY):

`4/5xx4/5xx4/5xx4/5xx4/5=(4/5)^5=1024/3125~~0.33=33%`

So the probability of you having at least one green vehicle is:

`1-0.33=0.67` or `100%-33%=67%`