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.
There are 12 inches in a foot. To find how many inches are in 5 feet, multiply by 12:
5*12 = 60 inches
Add the 8 additional inches:
60 + 8 = 68 inches
The answer is 68.
The average rate of change is 1
2-1=1
3-2=1
4-3=1