Question

There are 5 cars red , blue , white , black and green and five keys each opening one of the cars. I pick a key and try to open one of the cars. What is the probability that it opens the blue car?

Answer 1

is this supposed to be a trick question?

Answer 2

No

Answer 3

if not, then literally speaking i think it would be 1/5 = 20% is the probability to choose a key that will open the blue car.

Answer 4

My initial guess would be 1/5

Answer 5

HI!!

Answer 6

it has to open one of the cars right?

Answer 7

if you had 6 keys to choose from, it would be different

Answer 8

yes thats right. We are all pretty clever on OS! I's surprising how many people say its 1/5 * 1/5 = 1/25.

Answer 9

yay i am smart! thanks @welshfella for making me feel smart :)

Answer 10

that's Ok lol

Answer 11

:) good day to you all.

Answer 12

I think people just can't believe its so easy and over complicate it.

Answer 13

that's actually me most of the time ;)

Answer 14

I was surprised that you posted it anyway.

Answer 15

^^^^

Answer 16

If the question was you have to pick the green key then the green car - that would be 1/25.

Answer 17

yes. that would be a combination problem right?

Answer 18

or since you will pick the green key at the 1st ty, then the green car will hav a doubled chance which means 2/5. or that's what i understand from your question

Answer 19

No the 2 events are independent so you multiply the probabilities

Answer 20

Can i have the black car? ;;-;;

Answer 21

yea OK

Answer 22

I've been silly here. I got the question wrong . The way I wrote it the answer is 1/25 because you have to pick the blue key first and then pick the blue car.

But if you say that there are 5 cars and 5 keys - one for each car . You pick any key then try and open one of the cars then the answer is 1/5. - Because it doesn't matter which key you pick in the first place.

That was the original question . My only excuse is I'm tired!!