I think it’s d. A percent is out of 100 so it’s 156/100
The answer for the algebraic expression is 5-6t
Given:
Initial mass, m₀ = 23 g
Decay constant, k = 0.13
Exponential decay obeys the equation

where t = time, days
For half life, the mass is m = m₀/2.
Therefore

Answer: The half life is 5.33 days