Let A represents the event that DVD has a video effect.
So,
P(A) = 1.5 %
Let B represents the event that DVD has a audio defect.
So,
P(B) = 0.8 %
A ∩ B represents that DVD has both audio and video defect.
So,
P(A∩B) = 0.4%
Part a)
A ∪ B represents that DVD has a video or audio defect.
P(A∪B) = P(A)+P(B)-P(A∩B) = 1.5 + 0.8 - 0.4 = 1.9%
Thus the probability that the DVD purchased by the customer has a video or audio defect is 1.9%.
Part b)
The complement of P(A∩B) will represent the probability that the DVD does not have video or audio defect.
So, the probability that DVD purchased by customer does not have video or audio defect is 1 - 0.4 = 0.96%
3/8 = 0.375 hrs per wax
60 x 0.375 = 22.5 hrs for 60 cars
The total distance that will be covered is
25 - 3 = 22
If we let x be the head start that Ario will have before Miguel starts, then we have the equation
x / (22 - x ) = 1/4
Solve for x
x = 4.4
Ario will have to travel 4.4 meters before Miguel starts
Let
x = time of Byran's work
x + 10 = time of Andy's work
Rate is usually expressed a reciprocal. The total rate will be 12 minutes.
1/x + 1/(x + 10) = 1/12
The value of x will be 20 minutes.
Therefore Byran can take 20 minutes while Andy can take 30 minutes.