math, help
posted by student .
For this one i have no idea what formula or even how to set it up...
Tow 6sided dice are rolled. What is the porbability that the sum of the two numbers on the dice will be greater than 9?
Notation: n1 is the number that die 1 shows, n2 is the number that die 2 shows.
Then we want to know in how many ways you can have:
n1 + n2 > 9
where:
1 <= n1 <= 6
1 <= n2 <= 6
We know that without restrictions there are 36 possibilities (both n1 and n2 can then take 6 values), so we have to divide the number of possibilities by 36.
In this case the number of possibilities is not that large and you can just count all possibilities:
n1 = 4, n2 = 6
n1 = 5, n2 = 5
n1 = 5, n2 = 6
n1 = 6, n2 = 4
n1 = 6, n2 = 5
n1 = 6, n2 = 6.
by anychance do you know of a good website where it shows a similar example of how to use this type of formula....
I think the best thing you could do is study discrete mathematics from a good textbook.
I just found this PDF file:
http://www.cs.tau.ac.il/~odedr/teaching/discrete_math_fall_2005/dmbook.pdf
Respond to this Question
Similar Questions

algebra
two dice are rolled. if a 3 appears on either dice,then the two dice are rolled again and the two dice are added togather. if a 3 does not appear, then we ll add the two dice togather. if the sum of two dice is even ,i win and if the … 
math
suppose a pair of dice is rolled. Consider the sums of numbers on the top of the dice. Find the probabilities: a) P(5, given that the sum are odd) b) P(odd, given that the sum rolled is 5) c) P(7, given that one of the dice rolled … 
math
two dice are rolled find the probability of getting a 5 on either dice or the sum of both dice is 5 
math
two 6 sided dice are rolled.what is the probability the sum of the 2 numbers on the dice will be 4 Is 1/3 right? 
Help me please Maths
Calvin is playing a game of Dungeons and Dragons. In order to make it across the river, he needs to throw six 4sided dice, and have their sum be a multiple of 5. How many different dice throws result in Calvin making it across the … 
help please
Two six sided dice were rolled, and a friend tells us that the numbers that came up were identical. Find the probability that the sum of the numbers was as follows: a) 4 b) 11 c) an even number d) an odd number 
Probability
When two fair sixsided dice are rolled, there are 36 possible outcomes. Find the probability that either doubles are rolled or the sum of the two dice is 8. 
math
A fair 6 sided dice is marked with the numbers 1, 2, 3, 4,5, and 6. The dice is rolled three times and the results are added. How many different sums are possible? 
math
If two dice are rolled and their faces noted, find each of the following probabilities: a) the sum of the two dice is 8 b) both dice show even numbers c) the sum of the two dice is 8 OR both dice show even numbers d) the sum of the … 
math
A pair of 6 sided fair dice are rolled. If one of the dice shows an odd number what is the probability of the sum of the dice being 7 ?