Question

Q2) A bag contains 7 green, 8 black and 2 red balls. If 3 balls are drawn at random, determine the probability that; ( i.All are green ii.All are black iii. Two red and one black iv. At least one black v. One of each color​

Answer 1

Explanation:

total balls = 7 + 8 + 2 = 17

1)

7/17 x 6/16 x 5/15 = 7/17 x 3/8 x 1/3 = 7/17 x 1/8 = 7/136

2)

8/17 x 7/16 x 6/15 = 8/17 x 7/16 x 3/5 = 7/34 x 3/5 = 21/170

3)

2/17 x 1/16 x 8/15 = 2/17 x 1/30 = 1/17 x 1/15 = 1/255

4)

9/17 x 8/16 x 7/15 = 9/17 x 1/2 x 7/15 = 21/85 x 1/2 = 21/170

170/170 - 21/170 = 149/170

5)

7/17 x 8/16 x 2/15 = 7/17 x 1/2 x 2/15 = 7/17 x 1/15 = 7/255