3. Using the exponential formula for growth Ao = Ae^kT we can calculate k.
Ao is the starting amount = 30
Ae is final amount = 195
t is the amount of time = 5 hours
Now you have:
30 = 195e^5k
To solve for exponents you need to use logarithm
ln(30/195) = 5K
K = ln(30/195) / 5
K = -0.3744 ( Round answer as needed)
5. Triple is 3 times as much
So we have 3 = e^12r
ln(3) = 12r
r = ln(3) / 12
r = 0.092
r = 9.2%