Question

A scientist has 100 milligrams of a radioactive element. The amount of radioactive element remaining after t days can be determined using the equation f(t)=100(1/2)^t/10. After three days, the scientist receives a second shipment of 100 milligrams of the same element. The equation used to represent the amount of shipment 2 remaining after t days is 100(1/2)^t-3/10. After any time, t, the mass of the element remaining in shipment 1 is what percentage of the mass of the element remaining in shipment 2?

Answer 1

The answer is B. 81.2%