A10 gram sample of a substance thats used to detect explosives has a k-value of 0.1356. find the substances half-life in days. round your answer to the nearest tenth.

n=n0e^-kt

n0= 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 days.