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Determine the growth constant of a population that is growing at a rate proportional to its size, where the population doubles in size every 40 days and time is measured in days.

Time to Tripte Determine the growth constant of a population that is growing at a rate proportional to its size, where the population triples in size every 10 years and time is measured in years.

A population is growing exponentially with growth constant .05. In how many years will the current population triple?

lodine Level in Dairy Products If dairy cows eat hay containing too much iodine \(131,\) their milk will be unfit to drink. Iodine 131 has half-life of 8 days. If the hay contains 10 times the maximum allowable level of iodine \(131,\) how many days should the hay be stored before it is fed to dairy cows?

In \(1947,\) a cave with beautiful prehistoric wall paintings was discovered in Lascaux, France. Some charcoal found in the cave contained \(20 \%\) of the \(^{14} \mathrm{C}\) expected in living trees. How old are the Lascaux cave paintings? (Recall that the decay constant for \(^{14} \mathrm{C}\) is .00012.)