probability question (1 Viewer)

[akkjen]

answer is c
why dont i have to multiply by 4 since it can happen in 4 differ ways

 

[quickoats]

In total, there are 8 shoes the runner can choose from. The number of ways they can “choose” 2 shoes at random is 8C2=28, and out of those, there are 4 ways to choose a correct pair.

 

[Jig]

If you choose any pair of shoes with no restriction, the chance of you getting it is 8/8. Now you have a restriction, the next shoe has to match the colour of that first shoe, which is only a 1/7 chance. Therefore (8/8) * (1/7) is just 1/7. This is the more 2u way of doing it.

 

[akkjen]

If you choose any pair of shoes with no restriction, the chance of you getting it is 8/8. Now you have a restriction, the next shoe has to match the colour of that first shoe, which is only a 1/7 chance. Therefore (8/8) * (1/7) is just 1/7. This is the more 2u way of doing it.

since there are 4 pairs isnt there 4 ways we can do it so dont we have to times by 4 or am i trippin

 

[Carrotsticks]

since there are 4 pairs isnt there 4 ways we can do it so dont we have to times by 4 or am i trippin

You be trippin'

The 4 ways you can do it are already included in the 8/8. But I know what you're trying to do so let me provide an answer that more closely aligns with your thinking style.

Pretend that the 4 pairs are called A, B, C and D. Let's find the probability of matching "A" pair.

First shoe is A = 2/8
Second shoe is A = 1/7
So probability of AA = 2/8 * 1/7 = 1/28

But that's "AA" in particular. Why not "BB", "CC" or "DD"? So now we can multiply by 4 as you suggest.

1/28 * 4 = 1/7

*dabs*

 

[akkjen]

You be trippin'

The 4 ways you can do it are already included in the 8/8. But I know what you're trying to do so let me provide an answer that more closely aligns with your thinking style.

Pretend that the 4 pairs are called A, B, C and D. Let's find the probability of matching "A" pair.

First shoe is A = 2/8
Second shoe is A = 1/7
So probability of AA = 2/8 * 1/7 = 1/28

But that's "AA" in particular. Why not "BB", "CC" or "DD"? So now we can multiply by 4 as you suggest.

1/28 * 4 = 1/7

*dabs*

lol, ohhhhhhhhhhhh it makes sense! thanks heaps!
*dabs back*