Topscore #3 QR #40
Started by diene
okay so lets approach this problem by knowing a few things first.
on a fair die they're are 6 sides so your chance of rolling a four are 1/6
Now we also know that they're 10 combinations of two 4's and four other numbers. We know this by simply doing 2*5.
Now lets say we roll the die to get two 4's and 4 other random numbers
1/6*1/6*5/6*5/6*5/6 =125/7776
Now you multiply by 10 to give you all the possibilities of throwing this.
on a fair die they're are 6 sides so your chance of rolling a four are 1/6
Now we also know that they're 10 combinations of two 4's and four other numbers. We know this by simply doing 2*5.
Now lets say we roll the die to get two 4's and 4 other random numbers
1/6*1/6*5/6*5/6*5/6 =125/7776
Now you multiply by 10 to give you all the possibilities of throwing this.
Okay I am a bit confused on how many combinations...I don't get how you used 2*5
Okay lets say you roll the dice and get
44XXX
4X4XX
4XX4X
4XXX4
XXX44
XX4X4
........
you keep going and you'll find you have 10 or if you know the rick you can say you want 2 specific numbers out of 5 where order does not matter and do 5*2
44XXX
4X4XX
4XX4X
4XXX4
XXX44
XX4X4
........
you keep going and you'll find you have 10 or if you know the rick you can say you want 2 specific numbers out of 5 where order does not matter and do 5*2
If order mattered then it would be 5, right?
if order mattered you would do a permutation...i think.
This is how I solved it. I am sure they're are other ways. The best way to do it. Is to write out all the combinations so you can see it. There will be 10 combinations.
This is how I solved it. I am sure they're are other ways. The best way to do it. Is to write out all the combinations so you can see it. There will be 10 combinations.
Similar threads
