I am pretty sure it is 30. Hope it helps!!
Answer: 0.2857
<u>Step-by-step explanation:</u>
At least one teacher means exactly 1 or exactly 2 or exactly 3 teachers. Find the probability of each and add them up.

One teacher + Two teachers + Three teachers = 0.2857
<h2>
Answer:</h2>
B. 3
<h2>
Step-by-step explanation:</h2>
A tangent is a line that passes through exactly one point on a circle. For any point on a circle, the radius and tangent line through that point are always perpendicular to each other making a right angle. If two triangles touch each other externally, then there will be 3 lines making right angle with radius of the circles at the point of intersection of circle and tangents. These three tangent lines are shown below. They are the black, blue and green ones.
$7.35. All you do is multiply the two together
The line
is already written in the
form. This means that
is the slope. If two lines are perpendicular, their slopes are the anti-inverse of each other, i.e. their product is -1.
So, our perpendicular line has a slope of 
Finally, we want a line passing through (1,1) with slope
:
