Question

you roll 2 dice. Daw a table to show all the possible outcomes.
what is the probability that the total of the 2 dices is 9?

Answer 1

start with a roll of '1' on the first die and make a list...

Answer 2

ie (1,1) (1,2) (1,3) ....

Answer 3

then going on to '2' on the first die... if you get the same two numbers paired from two different rolls, disregard one of them

Answer 4

sorry i dont quite get what you mean with your second response?

Answer 5

make your list for the first die. When you go one to do the same for the second die you'll get some duplications, like (2,2) will be repeated. Ignore one of them, because it's the same roll whichever die your considering... ie there's only one way to roll (2,2)

Answer 6

try it and you'll see... you should end up with 36 pairs of numbers when you're done.

Answer 7

cool so i got 36 pairs, so do i not put in the table the 2,2 3,3 etc?

Answer 8

only once, there's only one way to roll (2,2) it doesn't matter which die you begin with...

Answer 9

so you have your 36 possible outcomes (pairings of values)...
now see how many pairings giver you a total of '9'

Answer 10

is it 1 in 6?

Answer 11

ie (3,6), (4,5) ....

Answer 12

how many outcomes give you a sum of 9 on two dice?

Answer 13

8?

Answer 14

which pairs?

Answer 15

(3,6) , (4,5) ,....

Answer 16

(3,6) (4,5) 6,3) (4,5) on one side and do i double it for dice 2?

Answer 17

no. so 4 outcomes give you 9

Answer 18

4 out of 36 total possible outcomes... so your odds of rolling a 9 are...?

Answer 19

1/9

Answer 20

yes:)

Answer 21

ha ha im a bit slow but i finally get it =) one more question, when i am doing up my chart do i only plot the 36 nos for dice 1 or do i add to my table dice 2 outcomes minus the 2,2 3,3 etc?

Answer 22

I just wanted you to see that when you'd done the table for the 1st die, you only get duplicate pairs if you do the same process for the second die... but I think you already had guessed at that because you got an answer of 36 total possible outcomes pretty quickly

Answer 23

ok, thank you sooo much for your help, you are the best!