Exponential Growth and Logarithms

So, I have these two problems for Calculus that I'm rather stuck on right now.

The information given for the first is this:

(Exponential growth)

Colony weight:

15 mg at 9:00 A.M.

25 mg at 11:30 A.M.

45 mg at ?

where 9:00 A.M. corresponds to t=0.

What's given for the next one is this:

"In the cold storage room, which is maintained at a constant temperature of 20° C, Detective Marino discovered the body of Dr. Expo’s assistant, Nat Log. The Detective measured the temperature of the body to be 34° C at 5:00 p.m. Two hours later, when Dr. Kay Scarpetta, the chief medical examiner, arrived to examine the bodies and evidence, she measured Nat’s body temperature to be 31.7° C.

Dr. Scarpetta knew that Newton’s Law of Cooling says that the temperature of a cooling object is given by the function

T

(*t*)=*Se*−*kt*+*M *

where *M *is the temperature of the surrounding environment, although she didn’t know either *S *or *k*. She did know that the normal body temperature of a living person is 37° C. "

And I'm supposed to find the missing times for both. Any help would be greatly appreciated!