2. A bag contains 7 white, 6 red and 5 black balls. Two
balls are drawn at random. The probability that they both
will be white is
Answers
Answer:
Given that
A bag contains 5 red, 6 white and 7 black balls
Total number of balls =5+6+7=18
Two balls are drawn ar random =
18
C
2
The probability that both balls are red
=
5
C
2
=
2×1×2!
5×4×3!
=10
The probability that both balls are black
=
7
C
2
=
2×1×5!
7×6×5!
=2!
The probability that both balls are red or both black =
8
C
2
10+21
=
2×1×16!
18×17×16!
31
=
153
31
P(A∪B)=
153
31
Answer: A bag contains 7 white, 6 red and 5 black balls. Two
balls are drawn at random. The probability that they both
will be white is 7/51
Step-by-step explanation:
Total number of balls in the bag = 7 white balls + 6 red balls + 5 black balls
= 18 balls
The probability of getting a white ball after first draw = 7/18
After first draw the total number of white balls in the bag is 6 and the total number of balls is also decreased from 18 t0 17
Now, the total number of balls in the bag = 17
The probability of getting a white ball in second draw is 6/17
Hence the probability of drawing two white balls from the bag is
probability after first draw × probability after second draw
⇒ (7/18)×( 6×17)
⇒42/ 306
⇒ 7/51
A bag contains 7 white, 6 red and 5 black balls. Two
balls are drawn at random. The probability that they both
will be white is 7/51.
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https://brainly.in/question/1350976
To know more about event in probability from the given link
https://brainly.in/question/1350976
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