I am sorry this is where I can get too.
Answer:
a) P(t>3)=0.30
b) P(t>10|t>9)=0.67
Step-by-step explanation:
We have a repair time modeled as an exponentially random variable, with mean 1/0.4=2.5 hours.
The parameter λ of the exponential distribution is the inverse of the mean, so its λ=0.4 h^-1.
The probabity that a repair time exceeds k hours can be written as:

(a) the probability that a repair time exceeds 3 hours?

(b) the conditional probability that a repair takes at least 10 hours, given that it takes more than 9 hours?
The exponential distribution has a memoryless property, in which the probabilities of future events are not dependant of past events.
In this case, the conditional probability that a repair takes at least 10 hours, given that it takes more than 9 hours is equal to the probability that a repair takes at least (10-9)=1 hour.


This shape is trapezoid
top of the trapezoid is 10 (12-2)
and the bottom is 4 (6-2)
the height in 3 (3-0)
so the area will be

the area is 21
Answer:

Step-by-step explanation:
If P partitions AB in the ratio 1:1, it means AP = ½ of AB, and PB = ½ of AB.
Therefore, P can be said to be a midpoint between A and B.
To find the coordinates of P, use the midpoint formula:
Midpoint (P) of AB, for A(3, 5) and B(1, 2) is given as:

Let 

Plug the values into the formula:


