Represent the decay of the substance by the equation
where
m₀ = initial mass
k = decay constant
t = time, years
Because the half life is 18 years, therefore
When m(t) = 63% of m₀, obtain
Answer:
The substance decays to 63% of its original amount in 12 years.
No because if you add all of the things she had already bought it would have been 6.09 and if she had bought more the total would’ve been 12.18
$3.25+$1.85+$0.99= 6.09
$6.09- $10.00= $3.91