Question

1. A bag contains 5 red balls 4 grean balls and 8 black balles.A ball is drawn at rondom from the bag. what is the probability that the ball drawn is
a) red ball
b) green ball
c) not red ball
d) either green or black
e) black
f) neither red nor black ​

Answer 1

According to the question, the bag contains:

• 5 red balls
• 4 green balls
• 8 black balls.

General formula for probability:

$\boxed{\pink{ \sf{p(e) = \dfrac{Number \: of \: Favourable \: outcomes}{Total \: number \: of \: outcomes} }}}$

For finding the probability of red ball :-

$\sf{p(\red{red \: ball)} = \dfrac{5}{5 + 4 + 8} }$

$\to \: \sf{p( \red{red \: ball)} = \dfrac{5}{17} }$

For finding the probability of green ball :-

$\sf{p (\green{green \: ball}) = \dfrac{4}{5 + 4 + 8} }$

$\to \: \sf{p( \green{green \: ball}) = \dfrac{4}{17} }$

For finding the probability of not red ball :-

$\sf{p(not \: red) = \dfrac{4 + 8}{17} }$

$\to \: \sf{p(not \: red) = \dfrac{12}{17} }$

For finding the probability of either black or green ball :-

$\sf{p(black \: or \: \green{green}) = \dfrac{8 + 4}{17} }$

$\sf{p(black \: or \: \green{green}) = \dfrac{12}{17} }$

For finding the probability of black ball :-

$\sf{p(black) = \dfrac{8}{17} }$

For finding the probability of neither red nor black :-

Neither red nor black = green

$\sf{p( \green{green}) = \dfrac{4}{17} }$