Q A bag contains 8 red, 6 white and 4 black balls. A ball is drawn at random
from the bag. Find the probability that the drawn ball is :
a) red or white
b) not black
Answers
Step-by-step explanation:
Total no. of balls in the bag is 18 (8 red, 4 black and 6 white)
Solution(i):
No. of red or white balls in bag is 14 (8 red and 6 white)
Therefore,
14
C
1
( Selecting 1 out of 14 items) times out of
18
C
1
( Selecting 1 out of 18 items) a red or white ball is picked.
Let E be the event of drawing a red or white ball from bag
We know that, Probability P(E) =
(Total no.of possible outcomes)
(No.of favorable outcomes)
=
18
C
1
14
C
1
=
18
14
=
9
7
Solution(ii):
No. of non-black balls in bag is 14 (8 red and 6 white)
Therefore,
14
C
1
( Selecting 1 out of 14 items) times out of
18
C
1
( Selecting 1 out of 18 items) a non-black ball is picked.
Let E be the event of drawing a non-black ball from bag
We know that, Probability P(E) =
(Total no.of possible outcomes)
(No.of favorable outcomes)
=
18
C
1
14
C
1
=
18
14
=
9
7
Solution(iii):
No. of neither black nor white balls in bag is 8 (8 red balls)
Therefore,
8
C
1
( Selecting 1 out of 8 items) times out of
18
C
1
( Selecting 1 out of 18 items) a neither white nor black ball is picked.
Let E be the event of drawing a neither white nor black ball from bag
We know that, Probability P(E) =
(Total no.of possible outcomes)
(No.of favorable outcomes)
=
18
C
1
8
C
1
=
18
8
=
9
4