Answer:
4/3
Step-by-step explanation:
multiply by the reciprocal
×
= 
Answer:
A, complementary angles sum up to 90°
Answer:
0.10 or 10%
Step-by-step explanation:
Since each student must take at least 2 courses, if no student took all three courses, the sum of the percentages would total 200% (counting each student twice). Therefore, the proportion of students taking all three courses is the difference between the sum of all percentages and 200%:

0.10 or 10% of the students take all 3 courses.
Since we know that:
C = 2πr
(With C = 36π ; Substitute in to the equation)
36π = 2πr (dividing both sides by 2π)
r = 18 cm