Two points are selected randomly on a line of length 32 so as to be on opposite sides of the midpoint of the line. In other words, the two points X and Y are independent random variables such that X is uniformly distributed over [0,16) and Y is uniformly distributed over (16,32]. Find the probability that the distance between the two points is greater than 9.

Solution :

Let us consider the squares be

If x ranges from the 0 to 16 and the y ranges from 16 to 32, we see that the boundary of the region  which goes from the .

And so it is easier to find the area of region where . This is the triangle with points as its vertices.

The area if the triangle is =  

                                         =

Now the entire area is  = 256

Then,

or

Thus the answer is

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3