Probability problems

[Awuah29]

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Anyone know how to tackle those problems ?
In a certain casino, you are paid winnings if you roll a seven with two die.
What are your chances of rolling a seven in one toss?
1/6
1/3
1/36
3/36
1/2

In a regular deck of fifty-two cards, what is the probability of drawaing a daimond on the first try?
13/26
1/13
1/4
1/26
1/52

What is the probability of rolling double threes in one toss of a nine sided die and a six sided die?
1/36
1/6
1/15
1/27
1/54

thanks guys!

 

[Awuah29]

What is the probability of six tails out of nine tosses of a fair coin?

p = probability of getting a tails (1/2)
C(x,y) where x = 9 and y = 6.
C(x,y) = x!/[y!*(x-y)!]

The equation to solve this is (just memorize it):

C(x,y)*p^(x)*(1-p)^(x-y)

Plug in the values for x and y and you should get 21/128


Is the any shortcut to solve that probleme above without memorizing this formula? x, and y is just confusing 😀

Any hint?

 

[DrTacoElf]

yeah for simple problems you can work out all possible combinations, but with ones that have larger number of tosses or chances you won't be able to do it. Peronally i'm resorting to the binomial myself in all cases.

 

[Awuah29]

heh taco,
i know you taken Dat very soon !
So do you know how to solve those problems
thanks!

 

[jjdaddy]

Anyone know how to tackle those problems ?
In a certain casino, you are paid winnings if you roll a seven with two die.
What are your chances of rolling a seven in one toss?
1/6
1/3
1/36
3/36
1/2

There are 6 ways of getting a seven:
die A die B
1 6
2 5
3 4
4 3
5 2
6 1

so, the odds of getting seven is 6/36(6x6) which is 1/6.

In a regular deck of fifty-two cards, what is the probability of drawaing a daimond on the first try?
13/26
1/13
1/4
1/26
1/52

There are 13 diamonds in a deck. 13/52 = 1/4

What is the probability of rolling double threes in one toss of a nine sided die and a six sided die?
1/36
1/6
1/15
1/27
1/54

only 1 three on each die, so 1/6 * 1/9 = 1/36