The amount remaining of a radioactive substance after t hours is given by

Question

A(t) = 100ekt. After 12 hours, the initial amount has decreased by 4%.

How much remains after 48 hours?

What is the half-life of the substance?

Answer 1

just did a question just like yours
http://www.jiskha.com/display.cgi?id=1448296657

follow the steps

for the half life, set the amount = 50 and solve for t

Answer 2

The amout remaining of a radioactive substance after t hours id given by A(t)=100e^kt. After12hours, the initial amount had decreased by 7%