Answer:
The probability that exactly one switch is good is

Step-by-step explanation:
The probability that a switch is defective is:

The probability that a switch is not defective is

Therefore, if two switches are selected, the probability that exactly 1 is good is:



If you are rounding it will be the same thing
Answer: The percent changed because it increased by 180%.
Step-by-step explanation:
Let x = total distance he covered
3x/4 by bus
1/2 . x/4 = x/8 by jogging
the remaining distance = x/8 by walking
thus x/8 = 800ft
x = 8 . 800 = 6400ft
the answer is D. all of the above