Question

A bag contains 3 red balls and 5 black balls. A ball drawn at random from the bag. what is the probability that the ball drawn is
(1) red ? (2) not red

Answer 1

No. of red balls = 3
no. of black balls= 5

1. Probability of getting a "red" ball = $\frac{no.\ of\ red\ balls}{total\ no.\ of\ balls } = \frac{3}{8}$

2.Probability of getting a "not red" ball
   = 1 - Probability of getting a "red" ball
   = 1-(3/8) 
   =5/8

Answer 2

Given=
No. of red balls = 3
No. of black balls= 5
Total number of ball = No. of red balls + No. of black balls = 3 + 5 = 8

1. Probability of getting a "red" ball = 

2.Probability of getting a "not red" ball 
   1 - 3/8 , 8 - 3/8           =5/8