Question

You roll 2 dice. What is the probability that the sum of the dice is greater than 7 and 1 die shows a 2? A 6 X 6 table of dice outcomes will help you to answer this question. Write fractions in lowest terms.

Answer 1

@terenzreignz

Answer 2

count!!

Answer 3

(2,6) works
so does (6,2)
i think that is all

Answer 4

Total number of possible outcomes = 6^2 = 36
Sum of the digits---No. of outcomes
02 ------------------------- 01
03 ------------------------- 02
04 ------------------------- 03
05 ------------------------- 04
06 ------------------------- 05
07 ------------------------- 06
08 ------------------------- 05
09 ------------------------- 04
10 ------------------------- 03
11 ------------------------- 02
12 ------------------------- 01
Total --------------------- 36
P(sum of the digits is odd) = P(A) = (2+4+6+4+2) / 36 = 18/36
P(sum of the digits > 6) = P(B) = (6+5+4+3+2+1) / 36 = 21/36
P(A and B) = (6+4+2) / 36 = 12/36
Required probability = P(A or B) = P(A)+P(B)-P(A and B)
=18/36 + 21/36 - 12/36
= 27/36
= 3/4

Answer 5

lol some other answer to some other question

Answer 6

that doesn't help:(

Answer 7

2,6 & 6,2 aren't the only ones

Answer 8

just count is all
how many fit the description

Answer 9

First notice that the sample space contains 6 x 6 = 36 possibilities. Now notice that our event space only contains those possibilities that show a 2 and have a sum greater than 7. The only way to have a sum greater than 7 is when 2 + x > 7, where x is some other number we rolled. Solve the inequality and we get:\[\bf 2+x>7 \implies x > 5\]The only other number we can roll which is greater than 5 is 6. Hence the two ways we can roll 2 dice and get a 2 and a sum greater than 7 is (2,6) or (6,2).

To computer the probability, we know there is 36 possible ways and only 2 ways that we want. \[\bf P(\sum > 7 \,, shows \ 2)= \frac{ n(A) }{ n(S) }=\frac{ 2 }{ 36 }=??\]

Answer 10

ok find another and show that i am not right

Answer 11

@music101

Answer 12

oh it has to be GREATER than huh? not equal to 7???

Answer 13

right!!

Answer 14

so itd be:
4,4
5,4
4,5
6,5
5,6

Answer 15

oh hell no

Answer 16

don't forget is says AND one die shows "2"

Answer 17

nnooooooooooo @music101 look at what I just said. There MUST BE A 2 and the sum MUST BE GREATER THAN 7

Answer 18

oh oops

Answer 19

@satellite73 I must say, you've readily improved at probability questions.

Answer 20

so it is just 2,6 & 6,2 then

Answer 21

YES!!!!

Answer 22

So 2 ways to get a 2 and a sum greater than 7 out of a total of 36 possible ways. So the probability is??? @music101

Answer 23

1/18?

Answer 24

YESESESE@!#!@# U DID IT!

Answer 25

thank u.. sorry probability is just a little confusing.. ugh, there were worse problems

Answer 26

I love them. If you got more questions, just post them and I'll help you out. @musicalcat98

Answer 27

ok ill post them now

Answer 28

who's musicalcat??

Answer 29

I think that probability is just nature's sinister way of showing mathematician's that they can't even count. Counting is the hardest part of probability, I think.