Answer:
a) 
b) 
Step-by-step explanation:
Part a
We assume that the parachutist lands at random point in the interval (x=A,y=B) we have a continuous random variable X. And the distribution of X would be uniform
. And the density function would be given by:

And 0 for other case.
The operation fails, if parachutist's distance to A is more than five times as much as her distance to B.
So the point P in the interval (A,B) at which the distance to A is exactly 5 times the distance to B is given by:

And we can find the probability desired like this:

And from the cumulative distribution function of X ficen by
we got:

Part b
For this case we assume that 
On this case we assume that 
The density function for the Gamma distribution is given by:

And on this case we can find the probability using the complement rule like this:

We can solve this problem with the following excel code:
"=1-GAMMA.DIST(1;2;1;TRUE)"
And if we do it by hand we need to do this:

Answer:
-8n+7
Step-by-step explanation:
the difference between the values is 8, as it decreases by 8, it withh be 8n
It does not start at 8 though, so you do 15-8 to find the different which is added on which is 7 in this case
Answer:
y =3x - 5
Step-by-step explanation:
Well one of the way to do this question is the formula given below your question, but for me, i rather do it this way
OK they gave u y=3x - 12
And they say another line is parallel, once u see the word parallel means they have the same angle, same slope, same gradient ( sorry if I give u the wrong terms, since I learn mine in Malay)
So first u got to understand the slope-intercept form
y = mx + c
y is your y coordinate
x is your x coordinate
m is your gradient ( as in how much the line slants)
c is the y - intercept, as in, if u draw a graph, the y-coordinate where your line touches the y-axis (the vertical line)
So since the say the both lines are parallel, so both of their "m" is the same that is 3. Why? Cuz just compare
y = mx + c
y = 3x - 12
Therefore the m is 3
Therefore u alredy got your first value, so put it in your slope intercept form
y = mx + c
y = 3x + c
Now how to find c? Very easy, just put in the value of y and x from the coordinate ( that the line youre finding is on) they gave u, just put the value in
They gave u
(1, - 2)
So when x = 1, y = - 2
Therefore put it in
y = 3x + c
-2 = 3 (1) + c
c = - 5
Since now u have your m and c value, your slope intercept form is done, just put it in
y = mx + c
y = 3x + (-5)
y = 3x -5
Answer: Her e-mail password is 
Step-by-step explanation:
You know that a part of Rivka's e-mail password is formed by the last four digits of her telephone number.
The exercise gives you the last four digits of Rivka's telephone number:

Now, in order to find the other numbers, you need to descompose
into its prime factors. Then:

Therefore, based on this, you can determine that her e-mail password is:
