Six hundred paving stones were examined for cracks, and 20 were found to be cracked. The same 600 stones were then examined for discoloration, and 29 were found to be discolored. A total of 562 stones were neither cracked nor discolored. One of the 600 stones is selected at random. Find the probability that it is cracked, discolored, or both.

a) probability that is cracked=1/30 (3.33%)

b) probability that is discoloured = 29/600 (4.83%)

c) probability that is cracked and discoloured =  11/600 (1.83%)

Step-by-step explanation:

assuming that each stone is equally likely to be chosen then defining the events C= the stone is cracked , D= the stone is discoloured , N= the stone is neither cracked or discoloured, then

P(C)= number of favourable outcomes/total number of outcomes = 20 stones/600 stones = 1/30 (3.33%)

P(D)= number of favourable outcomes/total number of outcomes = 29 stones/600 stones = 29/600 (4.83%)

the probability that is discoloured and cracked is P(C∩D) , where

P(C∪D)=P(C) + P(D)-P(C∩D)

and

P(C∪D)= 1- P(N)

thus

1- P(N)=P(C) + P(D)-P(C∩D)

P(C∩D)= P(N)+P(C)+P(D) -1

replacing values

P(C∩D)= P(N)+P(C)+P(D)=562/600 + 20/600 + 29/600 -1= 611/600 -1 = 11/600

thus

P(C∩D)=  11/600 (1.83%)

answer: 26

step-by-step explanation:

well, michelle wanted to measure the height of her school's flagpole she placed a mirror on the ground 48 feet from the flagpole then walk backwards until she was able to see the top of the pole in the mirror her eyes were 5 feet above the ground and she was 12 ft from the mirror using similar triangles find the height of the flagpole to the nearest tenth of a foot find the geometric mean of them pair of numbers. its easy math

b

step-by-step explanation:

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