The half life of plutonium is 250 years. If the starting mass is 750g find; An equation that models the mass of plutonium P(t) for t years from now. And find the amount of time required to reduce the plutonium to 200g
P(t) = 750g (1/2)^(t/250)
log(200/750) = (t/250) log(1/2)