Given:
Decay rate = 8% per day = 0.08
Initial mass = 2.43 kg
Let's find the mass of the sample after 3 days.
Apply the exponential decay formula:

Where:
A is the final amount
Po is the initial amount = 2.43
r is the rate = 0.08
t is the time = 3 days.
Thus, we have:

Therefore, the mass of the sample after 3 days is 1.91 kg.
ANSWER:
1.91 kg