<span> half life i= 78 hours
amount after 78 hours is 395 kg:
395 = 790e^(k*78)
Dividing by 790 and taking natural log
ln (395/790) = (k*78)
-0.6931 = 78k
-0.00888 = k
lets calculate how much is left after 18 hours:
Amount(18)
= 790e^(-0.00888*18)
Amount = 673.301 kg
hope this helps</span>
The answer to your question is A.
answer: 3.6
$12.79+$3.39=$16.18
$16.18+7.75% tax is $1.253
40 total spins
it landed on H 15 times which equals 15/40
15/40 reduces to 3/8
the answer is C 3/8
