Question 1048706
Let n be the original amount of pd-100. If it loses 93.75% of its' original amount, then the amount left equals 100-93.75=6.25%. So:
.0625=(.5)^t/3.634
.5^4=.5^t/3.634
t/3.634=4
t=14.536 or
log .0625=log .5^t/3.634
log .0625=t/3.634*log .5
(log .0625/log .5)*3.634=t
t=14.536 days. ☺☺☺☺