Question

Find P(blue and even).
1/10
3/5
7/10

Answer 1

P ( blue ) = ...
P ( even) = ...
P ( blue and even ) = .... x ....

Answer 2

7/10

Answer 3

7/10 is not correct.
I think it'd be easiest to just count the number of cards that are both blue and even to verify.

Answer 4

there is seven 2 blues and 5 evens

Answer 5

That'd be finding "Blue or Even" cards.
We are looking for "Blue AND Even" cards.

Answer 6

well its most likely 3/5

Answer 7

The idea is, we are looking at the chances that we choose the cards that both are blue and have an even number on them. This is what it means by "and."

Like, if we were looking for "green and odd," there are 2/10 that are green and odd: Green 3 and Green 5. They are both green and odd.

Answer 8

so am i wrong

Answer 9

@AccessDenied Let me give give simple explanation based on YOURS correct version :)

Answer 10

P(A and B) = P(A) + P(B) - P(A or B)
P ( blue and even ) = P ( blue ) + P ( even ) - P ( blue and even)

Answer 11

P ( blue ) = 2/10
P ( even) = 1/2
P ( blue and even ) = 1/10

Answer 12

@hithere Can you plug them in?

Answer 13

Oh, I have them backwards actually I think. o.O
P(A and B) = P(A) P(B)
P(A or B) = P(A) + P(B) - P(A and B)

Answer 14

Sorry, yes, I had it backwards. My fault. :(

Answer 15

Counting it does work, though. There is one card that is both blue and even: Blue 2.