A drug is eliminated from the body through urine. Suppose that for a dose of 10 milligrams, the amount A(t) remaining in the body t hours later is given by

A(t) = 10(0.7)^t

and that in order for the drug to be effective, at least 2 milligrams must be in the body.

(a) Determine when 2 milligrams are left in the body. (Round your answer to two decimal places.) (b) What is the half-life of the drug? (Round your answer to two decimal places.)