A card is drawn from a deck of well shuffled cards. Determine the probability that the card is either queen or heart.

Question

anonymous · Answer

How many queens are there in 52 cards??

hesan · Answer

4

anonymous · Answer

Yes..
So probability of selecting a queen will be 4 by 52..

Getting??

hesan · Answer

yes

anonymous · Answer

And now tell me, how many hearts are there in 52??

hesan · Answer

4

anonymous · Answer

Really??

anonymous · Answer

Total heart cards are :13

hesan · Answer

oh yes yes sorry

anonymous · Answer

can you tell me now the probability of choosing a heart??

hesan · Answer

this i dont understnd, 13 or 12?

anonymous · Answer

What 13 or 12??

There are 13 hearts are there..
Total cards are 52 now find the probability..

hesan · Answer

13/52

anonymous · Answer

Yes you are right..

Now the required probability is sum of these two probabilities..

Just add 4/52 + 13/52

can you add them??

hesan · Answer

17/52

anonymous · Answer

Yeah you got it right..

kinggeorge · Answer

Hold up. There's one thing you forgot. Both of those sums are counting the queen of hearts. That means you also need to subtract 1/52.

hesan · Answer

no but its the wrong ans

hesan · Answer

@KingGeorge: i dont get it

anonymous · Answer

There is queen in the heart too...
So @KingGeorge is saying right..

kinggeorge · Answer

Your solution should be 4/52+13/52-1/52. You need to subtract the queen since you've counted it twice.

anonymous · Answer

what is the probability of getting a queen of hearts 1/52
 you have to subtract it from the result..

hesan · Answer

dont understand why we subtract

zarkon · Answer

$$P(A\text{ or }B)=P(A)+P(B)-P(A\text{ and }B)$$

zarkon · Answer

general addition rule

hesan · Answer

P(A)=4/52

hesan · Answer

A and B are queen and heart. Right?

zarkon · Answer

yes

zarkon · Answer

Queen and Heart=queen of hearts

anonymous · Answer

What is the problem you are facing??

anonymous · Answer

See, there are 4 queens in 52 cads in which one queen is of heart..
Firstly we find the probability of queen..
Then we find the probability of heats but in there is a queen in hearts too, so probability of getting a heart will be 13/52

But in both the probabilities there is one intersection that is the queen of hearts..

So, total probability will be :

$$= \frac{4}{52} + \frac{13}{52} - \frac{1}{52}$$

hesan · Answer

@waterineyes: Oh thank you, I get it now!

anonymous · Answer

Welcome dear..