Answer
There will be around 42 grams of debris left after 14 days.
Work Step by Step
This involves exponential decay since the radioactive material decays at a rate of 4 percent each day.
RECALL:
Exponential decay is represented by the formula
$y=C(1-r)^x$
where
C = initial/original amount
r = decay rate
x = number of time intervals
The given situation has:
C = 75 grams
r = $4\%$ per day
x = 14 days
Substitute these values into the given formula above to have:
$y=75(1-4\%)^{14}
\\y=75(1-0.04)^{14}
\\y=75(0.96^{14})
\\y \approx 42$
