Initially 100 milligrams of a radioactive substance was present. After 6 hours the mass had decreased by 7%. If the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (Round your answer to one decimal place.)

The amount remaining after 24 hours is 17.5 milligrams.

Step-by-step explanation:

The rate of decay is proportional to the amount of the substance present at a time

The equation is

Rate=k*amount remaining at (time)

Where k = constant of proportionality.

So we don't know the value of k, let's find it.

7 = k (70) (6)

K = 1/60

Amount remaining after 24 hours

7 = 1/60 * x * (24)

(60*7) / 24 = x

17.5 = x

The amount remaining after 24 hours is 17.5 milligrams.