Question

A box has 13 white clips, 7 blue clips and 6 green clips. what is the probability that, if 2 clips are drawn from the box in succession, one is blue and other is white ?

Answer 1

Solution :-

Number of white clips = 13

Number of blue clips = 7

Number of green clips = 6

Total clips = 26

Number of ways that 2 clips are drawn from total of 26 clips = 26c₂

= (26 × 25)/(1 × 2)

= 650/2

= 325 ways

Number of ways that 1 white and 1 blue clip is selected = (13c₁) × (7c₁)

= 13 × 7

= 91 ways

Total probability = 91/325

= 7/25

Answer.

Answer 2

White clips = 13

Blue clips = 7

Green clips = 6

Total clips = 13 + 7 + 6 = 26

Find the probability of getting a blue and a white clip:

P( 1 blue + 1 white ) = P(blue then white) + P(white then blue)

P( 1 blue + 1 white) = (7/26)(13/25) + (13/26)(7/25)

P( 1 blue + 1 white) = 7/50 + 7/50

P( 1 blue + 1 white) = 14/50

P( 1 blue + 1 white) = 7/25

Answer: The probability is 7/25