One of the main contaminants of a nuclear accident, such as that at chernobyl, is strontium-90, which decays exponentially at a rate of approximately 2.5% per year.

(a) write the ratio of strontium-90 remaining, p , as a function of years, t , since the nuclear accident.

Step-by-step explanation:

We know that the general form of the exponential decay formula is

, where y is final amount remaining after t time, A is the original amount and r is the rate of decay

Now, the ratio of strontium-90 remaining, p , as a function of years, t , since the nuclear accident.

Hence, the ratio of remaining since the nuclear accident is

t = 3

step-by-step explanation:

put t = 3 in this expression :

(3²-1)(3²-2)(3² - 3)(3² - 4) = 8×7×6×5 = 56×30 = 1680

answer4 to the second power is 16

and 4 to the third power is 64,