blue marbles
y = yellow marbles
Sum = b+y
The <span>chance of a blue marble being drawn first is:
b / (b+y) = 0.55
</span>The <span>chance of a blue marble being drawn first then a yellow next is:
</span>b / (b+y) * y / (b+y-1) = 0.37
This can be solve easily by using a theorem of Bayes
0.37/0.55 = .67 or 67%
The number:

is going to be between the numbers 563 and 564; since 10 squared equals 100 and the decimal point will move to places to the right.
Therefore, the answer is D.
The domain and the range is [-6 to +inf)
Well. You start with two rabbits, and it triples every month, so:
0 months: 2 rabbits.
1 month: 2*3 = 6 rabbits.
2 months: 6*3 = 18 rabbits.
3 months: 18*3 = 54 rabbits.