Half life formula is,
<span>0.5=<span>e<span>k∗t</span></span></span>
where,
k=decay constant
t=time
substitute time, we get
<span>0.5=<span>e<span>k∗3.80</span></span></span>
taking natural logarithm on both sides, we get,
<span>ln(0.5)=k∗3.80</span>
or,
<span>ln(0.5)/3.80=k</span>
<span>k=0.182</span><span>(ANSWER)</span>
