Question

17. A box contains 5 red balls. 7 white balls and 8 green balls. If we take a ball from
the box without looking into it, then
a) What is the probability that the ball is red.
b) What is the probability that the ball is black.
c) What is the probability that the ball is not white.
d) What is the probability that the ball is either red or white.
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Answer 1

Answer:

a) Number of red balls = 5

Total number of balls = 5+7+8 = 20

Hence, probability of getting red ball = 5/20 = 1/4

b) Number of black balls = 0

Hence, probability of getting a black ball is 0.

c) Number of red and green balls = 5+8 = 13

Total number of balls = 20

Hence, probability that the ball is not white = 13/20

d) Number of red and white balls = 5+7 = 12

Total number of balls = 20

Hence, probability that the ball is red or white = 12/20 = 3/5

Answer 2

RED BALLS = 5

RED BALLS = 5 WHITE BALLS = 7

RED BALLS = 5 WHITE BALLS = 7GREEN BALLS = 8

TOTAL NO. OF BALLS = 20

a) P(RED BALL) = 5/20 = 1/4

b) P(BLACK BALL) = 0/20 = 0

c) P( NON-WHITE BALLS) = 13/20

d) P(RED/WHITE BALLS) = 12/20 = 3/5