For part (a) the answer is 400 grams for part (b) 198.63 grams and for part (c) 20 years.
<h3>What is exponential decay?</h3>During exponential decay, a quantity falls slowly at first before rapidly decreasing. The exponential decay formula is used to calculate population decline and can also be used to calculate half-life.
We have an equation for radioactive decay:
a) Plug t = 0
m(0) = 400 grams
b) plug t = 20 years
After solving:
m(20) = 198.63 grams
c) Plug m(t) = m(0)/2 = 400/2 = 200 grams
x = 19.80 years ≈ 20 years
Thus, for part (a) the answer is 400 grams for part (b) 198.63 grams and for part (c) 20 years.
Learn more about the exponential decay here:
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