Question

You are rolling two 6-sided dice and examining the sum of the two dice (for example, if you roll a 3 and a 5, this is an 8).

a) What is the probability of rolling a sum of 7?
b) What is the probability of rolling a sum of 11?
c) What is the probability of rolling a sum of 7 or 11?
d) What is the probability of rolling a sum of 7 and 11?

Answer 1

probability of rolling 7 is 1/6

Answer 2

ok

Answer 3

the way i do these is make a table that is 6x6

Answer 4

then add the corresponding terms...so it would look like this
1 2 3 4 5 6 7 8
1 2 3....
2 3
3 4.............
4
5
6
7
8

Answer 5

Ok i see!:) what about the rest

Answer 6

add them all up

Answer 7

and for the probability of summing a 7...would be counting the number of 7's when you add it all up. divided by 36

Answer 8

so a i got 1/6 right?

Answer 9

where do i start for b?

Answer 10

1 2 3 4 5 6
1 2 3 4 5 6 7
2 3 4 5 6 7 8
3 4 5 6 7 8 9
4 5 6 7 8 9 10
5 6 7 8 9 10 11
6 7 8 9 1011 12

Answer 11

so a is 7/36?

Answer 12

thats what it should look like...excluding the first row and first column. count up the number of 7's along the diagnol. And get 6
so 6/36=1/6

Answer 13

thats what i meant sorry ok i get a

Answer 14

yes and 11 would be 2/36

Answer 15

ok ya

Answer 16

ignore what i typed earlier..it does not go up to 8. Its a 6 sided die

Answer 17

are you in AP statistics?

Answer 18

now what do i do for c and d

Answer 19

yes. and so am i wrong

Answer 20

(a) 1/6

(b) 2/36

(c)

Answer 21

correct

Answer 22

for or you add.
and for and you multiply

Answer 23

and for c?

Answer 24

its 3/36 or 1/12?

Answer 25

because the trials are indpendent, add 6/36 + 2/36 and get 8/36

Answer 26

ok and d?

Answer 27

for d) the trials are independent so you can multiply the probabilities: 1/6 (2/36)=2/216

Answer 28

ok thanjs!

Answer 29

sure

Answer 30

and A card is drawn from a standard deck of 52 cards (13 cards in each of four different suits). What is the probability that the card is a heart (one of the four suits)? would be 0.25 right??

Answer 31

it would help alot if you made me a fan :P

Answer 32

yes