Answer:
A. More students prefer Model A1 calculators than the Model C3 calculators.
For this problem, the most accurate is to use combinations
Because the order in which it was selected in the components does not matter to us, we use combinations
Then the combinations are 
n represents the amount of things you can choose and choose r from them
You need the probability that the 3 selected components at least one are defective.
That is the same as:
(1 - probability that no component of the selection is defective).
The probability that none of the 3 selected components are defective is:

Where
is the number of ways to select 3 non-defective components from 117 non-defective components and
is the number of ways to select 3 components from 120.


So:

Finally, the probability that at least one of the selected components is defective is:

P = 7.4%
Answer:
55 miles
Step-by-step explanation:
Given data
DIstance = 825 miles
Time = 15 hours
Speed= distance/time
Speed= 825/15
Speed= 55 miles per hour
Given that we want to find the distance traveled in 1 hour, we have
Distance= Speed*time
Distance= 55*1
Distance= 55 miles
Hence the car will travel 55 miles in 1 hour
I think 1 is the only common factor of both 0.20 and 215 but I'm not 100% certain