A bag contains 6 red, 8 black and 4 white balls. A ball is drawn at random. What is the probability that ball drawn is not black?
A bag contains 6 red, 8 black and 4 white balls. A ball is drawn at random. What is the probability that ball drawn is not black?
4 Answers
Total no. of possible outcomes = 18 {6 red, 8 black, 4 white}
Let E ⟶ event of drawing black ball.
No. of favourable outcomes = 8 {8 black balls}
Probability, P(E) = (No. of favorable outcomes)/(Total no. of possible outcomes) = 8/18 = 4/9
Bar E⟶ event of not drawing black ball
P(Bar E)=1 − P(E)
= 1 − 4/9 = 5/9
Total numbers of red balls = 6
Number of black balls = 8
Number of white balls = 4
Total number of non-red balls = 6 + 8 + 4 = 18
Number of non-black balls are = 6 + 4 = 10
Probability of getting a non-black ball is = Total number of non-black balls/Total number of balls
= 10/18
= 5/9
∴ Probability of getting a non-black ball is 5/9
Total numbers of red balls = 6
Number of black balls = 8
Number of white balls = 4
Total number of Non red balls = 6 + 8 + 4 = 18
Number of non black balls are = 6 + 4 = 10
Probability of getting a non black ball is = \(\frac{Total\,number\,of\,non\,black\,balls}{Total\,number\,of\,balls}\) = \(\frac{10}{18}=\frac{5}{9}\)
Sample space, n(S) = 18
Number of events of getting balls not black,
n(E) = 10
∴ P(E) = \(\frac{n(E)}{n(S)}\) = \(\frac{10}{18}\) = \(\frac{5}9\)