An initial amount of a radioactive substance y0 is given, along with information about the amount remaining after a given time t in appropriate units. For an equation of the form No Image that models the situation, give the exact value of k in terms of natural logarithms y0 = 60 g; After 3 h, 20 g remain

y0 = 60 g; Después de 3 h, quedan 20 g.