Question 1190431
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Half-life formula
y = a*(0.5)^(x/h)
Alternatively, you can represent the 0.5 as 1/2


a = initial amount
h = half-life, the amount of time it takes to cut in half
x = number of years
y = amount left over after x years pass by


We have the following
a = 40 grams
h = 9 years
x = 23.5 years


So,
y = a*(0.5)^(x/h)
y = 40*(0.5)^(23.5/9)
y = 6.54692287587487 approximately
y = <font color=red>6.55 grams</font>
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