A 31 gram sample of a substance that's a by-product of fireworks has a k-value of
0.1173.
N = Noe
-kt
No = initial mass (at time t = 0)
N = mass at time t
k = a positive constant that depends on
the substance itself and on the units
used to measure time
t = time, in day
Find the substances half-life in days round answer to nearest tenth