the half-life of a substance is 15 days. there's 2.5 grams of the substance initially.type an expression for the amount of substance as a function of t. when will there be less than 1 g remaining?

Question

f(t) = __ (simplify your answer)

there will be less than 1 gram remaining after about __ days. (round to the nearest tenth as needed)

Answer 1

A(t) = 2.5(0.5)^t/15

1 > 2.5(0.5)^t/15

0.4 > (0.5)^t/15

ln 0.4 = (t/15)(ln 0.5)

Can you calculate t and answer?