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Comment on 2nd Ball is Yellow
Can we solve this problem
Sure, give it a try.
Sure, give it a try.
Hi,
I tried using complement rule, but I got 2/25 instead of 1/25, can you analyze where I went wrong?
P( having second ball yellow)= 1-P( 2nd not being yellow)
= 1-P( 2nd being either red+ 2nd being green)
= 1-(12/25 x 12/24+ 12/25 x 11/24+ 12/25 x 12/24 +12/25 x11/24)
= 1-( 12/25 + 11/25)
= 1-23/25
= 2/25 (what went wrong?)
It's hard to tell, because
It's hard to tell, because you haven't really explained all of your steps. However, I believe you forgot to include P(1st ball is yellow and 2nd ball is ANY color)
This probability = (1/25)(24/24) = 1/25
I think this is your missing 1/25
I have a doubt here. The
In order for the 2nd ball to
In order for the 2nd ball to be yellow, the 1st ball must be NON-YELLOW. So, we have to factor that into our equation.
That is, P(2nd ball yellow) = P(1st ball is not yellow AND 2nd ball is yellow)
We can't just assume that the first ball is not yellow, since there's a 1/25 chance that the first ball is yellow.
Cheers,
Brent
I don't get it... it says the
SO:
P(any ball AND yellow ball) = 25/25 x 1/24 = 1/24
Why do we have to say that the first ball is NOT yellow...?
WAIT! I think I figured out the answer while typing this... this is true because we have only 1 yellow ball!
TRICKY question! Read the question carefully ya'll.
Good catch, KB23! :-)
Good catch, KB23! :-)