0.073 mg sample will remain
Explanations:The final amount of a substance after t years given the initial amount and the half life is expressed as:
[tex]A(t)=A_0(\frac{1}{2})^{\frac{t}{x}}[/tex]where A(t) is the amount after time t
x is the half life
A₀ = initial amount = 75 mg
t = 75 days = 75/365 = 0.2055 years
Half life, x = 7.5 days = 0.02055 years
Substitute these values into the formula given
[tex]\begin{gathered} A=75(0.5)^{\frac{0.2055}{0.02055}} \\ A\text{ = 75(0.5)}^{10} \\ A\text{ = }0.073\text{ mg} \end{gathered}[/tex]0.073 mg sample will remain
