a) is correct, but you should have brackets around the complete denominator. The way you typed it, it is only divided by (2x+10)
x(x + 10)/( (2x + 10)(2x + 9) )
b) So now we have an actual numerical case
and let's just follow the same argument you did in a)
blacks = 5
whites = 15
prob(black, then white) = (5/20)(15/19)
= 75/380
= 15/76
While playing a game, Rachel pulls two tiles out of a bag without looking and without replacing the first tile. The bag has two colors of tiles--black and white. There are 10 more white tiles than black tiles.
a. Write and simplify an expression that represents the probability that Rachel will pick a black tile, then a white tile.
A: x(x + 10)/(2x + 10)(2x + 9)
b. What is the probability that Rachel pulls a black tile and then a white tile if there are 5 black tiles in the bag berfore her first pick? Round your answer to the nearest hundredth
im having trouble on figuring out the steps to solve b.
3 answers
number or blacks = b
number of whites = b+10
total - b +b+10 = 2 b+10
black first
b/(2b+10)
now we have b-1 blacks
we have b+10 whites still
total = 2b+9
b/(2b+10) * (b+10)/(2b+9)
note - not 2b+10 in numerator
number of whites = b+10
total - b +b+10 = 2 b+10
black first
b/(2b+10)
now we have b-1 blacks
we have b+10 whites still
total = 2b+9
b/(2b+10) * (b+10)/(2b+9)
note - not 2b+10 in numerator
sorry, read reply wrong. You have it fine