The answer is C because you do PEMDAS and then add the 5 from the other side
That amount, which I assume you're asking about, is a 4 degree drop in temperature each week.
Answer: 50%
There are 2 sides, one of which is tails, so
P(tail) = 1/2 = 0.50 = 50%
0.12 can be written as 12/100 or 3/25. It is very much a rational number as no square root is involved in the fractional form of the number.