Question

A bag contains 2 red checkers and 6 black checkers. a checker is selected, kept out of the bag, and then another checker is selected. what is p(black, then red)?

Answer 1

Total checkers = 2 + 6 = 8
P(black, then red) = (6/8)(2/7) = 3/14

Answer: 3/14

Answer 2

A bag contains 2 red checkers and 6 black checkers. a checker is selected, kept out of the bag, and then another checker is selected.

Total checkers = 2 red + 6 black = 8 checkers

p(black, then red)

Probability ( selecting checker) =
`(numbe of selected checker )/(total checkers)`

P( black) =
`(6)/(8)`

1 black is selected so remaining 7 checkers

P( red) =
`(2)/(7)`

p(black, then red) =
`(6)/(8) * (2)/(7)`

=
`(12)/(56)`

Divide numerator and denominator by 4

So P(black, then red) =
`(3)/(14)`