An urn contains 9 red, 7 white, and 4 black balls. A ball is drawn at random. Find the probability that the ball is drawn is

red

We know that,

Probability of occurrence of an event

By permutation and combination, total no.of ways to pick r objects from given n objects is ⁿC_r

Now, total no.of ways to pick a ball from 20 balls is ²⁰c₁ = 20

Our desired output is to pick a red ball. So, no.of ways to pick a red ball from 9 red balls (because the red ball can be picked from only red balls) is ⁹c₁ = 9

Therefore, the probability of picking a red ball

Conclusion: Probability of picking a red ball from 9 red,

7 white and 4 black balls is