No, a & b are not independent if they're mutually exclusive.
Mutually exclusive means the two events cannot occur simultaneously. So if "a" happens "b" cannot. In contrast, two events are independent if the occurrence of one has no effect on the occurrence of the other.

This result is actually true for any exterior angle. The exterior angle of a triangle is equal to the sum of the two remote angles, and above is a short proof of it.
The answer to the question is letter "D. Commutative Property of Addition". The property states that if there are two numbers which we may represent by a and b, the value of a + b is equal to the value of b + a. The given, 8 + 5.3 = 5.3 + 8 is an example of this property.
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Answer: 2x+4y+12z (choice B)</h3>
Work Shown:
x = amount of rent paid per half year
2x = amount of rent paid annually
y = amount spent on groceries per quarter
4y = amount spent on groceries annually
z = amount spent on a transit pass monthly
12z = amount spent on transit pass annually
2x+4y+12z = total amount of money spent annually