Question

In a box, there are 9 red balls, & white balls and 3 black balls. One hall is taken out
of the bag. Find the probability that it is : (1) White (11) red or black (in) not red​

Answer 1

Correct question :-

In a box, there are 9 red balls, 8 white balls and 3 black balls. One ball is taken out of the bag.

Solution :-

Total number of balls = 9 + 8 + 3 => 20

1) P(White balls) = Number of white balls/Total number of balls

=> $\dfrac{8}{20}$

=> $\dfrac{2}{5}$

2) P(Red or Black balls) = Number of red and black balls/Total number of balls

=> $\dfrac{9 + 3}{20}$

=> $\dfrac{12}{20}$

=> $\dfrac{3}{5}$

3) P(not red) = Number of balls except red / Total number of balls

=> $\dfrac{8 + 3}{20}$

=> $\dfrac{11}{20}$