We'll say beginning amount is 100
Ending Amount = Beginning Amount / 2^n where n is the number of half-lives
100 hours mean six and 2/3 half-lives will elapse
Ending Amount = 100/2^(6.666666)
Ending Amount = 100 /
<span>
<span>
<span>
101.59
</span></span></span>Ending Amount =
<span>
<span>
<span>
0.9843488532
</span>
</span>
</span>
So if we started with 100 grams after 100 hours (or 6.6666666 half-lives) we would only have <span>
<span>
0.9843488532
</span>
grams remaining.
http://www.1728.org/halflife.htm
</span>
<span>1.6625 x 10−21</span>
<span>mass of one helium atom x 250 </span>
Express 250 as 2.50.
(6.65 x 10−24)(2.50 x 102)
16.625 x 10<span>−22</span>
40% of 200 is 80 so 120 were sold at the door
D=61d+30d=91d,
S=300+30d
S<D
300+30d<91d
300<61d
d>4.91 Since days are integers,
The skier would have to go at least 5 days to make the season pass less expensive than using the daily pass.
