First thing first, you have to use the proportion formula(is over of is a percent over 100).
Is=40
Of= n,
%= 30.
After setting that up and everything, your answer is 140.
The two events that are disjoint or mutually exclusive is getting a head and a tail at the same time. It because if you are going to flip a coin the result can either be head or tail but not both. The value of the two events occurring at the same is 0.
Slope = (y2 - y1)/(x2 - x1) = (1 - 3)/(-2 - (-5)) = -2/(-2 + 5) = -2/3
For perpendicular lines, m2 = -1/m1 = -1/(3/8) = -8/3
A line passing through point (-4, 0) and parallel to the y-axis is x = -4
radius = diameter/2 = 10/2 = 5
center of circle = midpoint of diameter = ((-3 + 5)/2, (1 + 7)/2) = (2/2, 8/2) = (1, 4)
Required equation is (x - 1)^2 + (y - 4)^2 = 5^2
(x - 1)^2 + (y - 4)^2 = 25
for the second one, cot(θ) = -1, bear in mind that cotangent is cosine/sine, so where both of them are the same values BUT different signs, you'd get a -1 from their fraction, and that happens at halfway in II and IV Quadrants, since on those quadrants both of them are of different signs.