Question

Q2. a basket contains 5 white and 9 black balls. there is another basket which contains 7 white and 7 black balls. one ball is to drawn from either of the two baskets. what is the probability of drawing a black ball? (a) 3/7 (b) 5/7 (c) 4/7 (d) 8/15 (e) none of these

Answer 1

for a basket probability is 9/14

for b basket probability is 7/14

now probability of a and b is 1*2

so 9/14*1/2 + 7/14*1/2 = 16/28 = 4/7

Answer 2

Answer:

Option C is correct.

Step-by-step explanation:

Let Basket 1 contain 5 white ball and 9 black ball.

Basket 2 contain 7 white ball and 7 black ball.

Total no of balls in Basket 1 = 9 + 5 = 14

Total no of balls in Basket 1 = 7 + 7 = 14

Probability = $\frac{NO\:of\:favourable\:outcome}{Total\:no\:of\:\:outcome}$

Probability of drawing a Black ball from Basket 1 =  $\frac{9}{14}$

Probability of drawing a Black ball from Basket 2 =  $\frac{7}{14}$

Probability of selecting a basket =  $\frac{1}{2}$

Probability of drawing black ball from any basket = $\frac{9}{14}\times\frac{1}{2}+\frac{7}{14}\times\frac{1}{2}=\frac{9}{28}+\frac{7}{28}=\frac{16}{28}=\frac{4}{7}$

Therefore, Option C is correct.