A bag contains 5 red, 6 blue and 7 black cards.If one card is drawn at random find the probability that it is black. About the author Ayla
Step-by-step explanation: 153 31 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 P(A∪B)= 153 31 Reply
Step-by-step explanation:
153
31
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
P(A∪B)=
153
31