Find the approximate age of the vertical Stonehenge rocks and the horizontal Stonehenge rocks.
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The vertical stones were found to have 1.78x10-9 grams of carbon-14. It is estimated it originally would have contained 3.31x10-9 grams.



The horizontal top stones were found to have 1.98x10-9 It is estimated it originally would have contained 3.1x10-9 grams.




About how long did it take to complete Stonehenge?

Please answer how long it took to complete Stonehenge, this is an algebra 2 assignment that uses carbon dating to find the answer. If it helps here's the formula I was given to help solve:

Half-Life Formula:[tex]A=A_{0} (\frac{1}{2} )^{\frac{t}{h} }[/tex]