Question

Please help me the answer are
98%
17.5%
2.0%
1.4%

Answer 1

We have

A = 100(0.5)^t

where t is in half-life units, t=1 is 35 days after t=0.

The daily decay rate is the decay after 1 day, which corresponds to t=1/35

0.5^(1/35) = 0.98039...

Answer: 98.0%  first choice