Question

From a standard deck of playing cards, a card is selected at random.
Find the probability of the event
The card selected is a heart or a queen

Answer 1

@ganeshie8 can you help me understand how to solve?

Answer 2

@zepdrix

Answer 3

Let's get some information organized.

How many hearts in the deck? :)

Answer 4

no 13 sorry

Answer 5

Ok good.
And 4 queens.

Answer 6

yes

Answer 7

This word OR is telling us that we want one of these 13 cards OR one of these 4 cards. It's less restrictive than the AND word.

So we simply add our two groups together.
13 + 4 = 17

But we have a slight problem.
There was an overlap!
Because one of our queens is one of our hearts, right?

Answer 8

Because there is a queen of hearts*

Answer 9

yes

Answer 10

So we have to subtract the `intersection of these groups`.

P(heart OR queen) = P(heart) + P(queen) - P(intersection)
P(heart OR queen) = 13 + 4 - 1

Answer 11

And if we want a probability,
we need to divide this number of cards by the `total`.

Answer 12

therefore it will be 16/52?

Answer 13

4/13?

Answer 14

yay good job \c:/

Answer 15

alright thank you so much for helping me understand :)

Answer 16

np

Answer 17

what would it be if there was no intersection? would it just n=be 17/52?

Answer 18

@zepdrix