Question

1. A bag contains 9 black and
12 white balls. One ball is
drawn at random. What is the
probability that the ball drawn
is black?​

Answer 1

• The Probability of getting a black ball is = 3/7

Step-by-step explanation:

Given:

A bag contains

• 9 black balls
• 12 white balls

To find:

The probability of getting a black ball

Now,

To total number of balls in the bag = Sum of black balls and white balls

Total number of balls = 9 + 12 = 21

So,

• Total possible outcomes = 21

Also,

The favorable outcome = black balls

The number of favorable outcome = 9 black balls (in total)

Thus,

P(getting a black ball) = (Number of favorable outcomes)/(Total number of possible outcomes)

• P(getting a black ball) = 9/21 = 3/7

Answer 2

Given:

A bag contains

• 9 black balls
• 12 white balls

━━━━━━━━━━━━━━━━━━

Need To find:

• What is the probability of getting a black ball

━━━━━━━━━━━━━━━━━━

Solution :

Total number of balls in the bag

=Total outcomes

=Number of black balls + Number of white balls

= 9 + 12

= 21

The number of black balls = 9

━━━━━━━━━━━━━━━━━━

We know,

Probability

= Number of favourable outcome ÷ Total number of expected outcomes

Thus,

Probability of getting a black ball

$= \dfrac{9}{21}$

$\red{= \dfrac{3}{7}}$