Question

a man draws 3 balls from an urn counting 5 white and 7 black balls he gets rs 10 for each white ball and rs 5 for each ball find his expectation

Answer 1

Step-by-step explanation:

Probability of getting RS 10 = Probability of getting white ball=  

Number of white balls÷ Total number of balls

5÷12

Probability of getting RS 5= Probability of getting black ball

Number of black balls÷Total number of balls

7÷12

Probability of getting Rs 30= Probability of getting 3 black balls= 5³÷12³

Probability of getting Rs 15= Probability of getting 3 white balls= 7³÷12³

probability of getting Rs 25= Probability of getting 2 black and 1 white= 5²×7÷12³

Probability of getting RS 20 = Probability of getting 2 white and 1 black=7²×5÷12³