Suppose a sample of a certain substance decayed to 69.4% of its original amount after 300 days. (Round your answers to two decimal places.) (a) What is the half-life (in days) of this substance

The half-life of this substance is of 569.27 days.

Step-by-step explanation:

Amount of a substance after t days:

The amount of a substance after t days is given by:

In which P(0) is the initial amount and k is the decay rate, as a decimal.

Suppose a sample of a certain substance decayed to 69.4% of its original amount after 300 days.

This means that . We use this to find k.

So

What is the half-life (in days) of this substance?

This is t for which P(t) = 0.5P(0). So

The half-life of this substance is of 569.27 days.

to find the perimeter, you add up all the lengths of the sides. in this case you would have to add up 18+22+40+80 which equals 160.