Does anyone want to help me on 2 half life questions?

Question

anonymous · Answer

1. The half-life of a carbon-14 is 5730 years. Carbon-14 can be used to date objects that are a maximum of about 58,000 years old. Approximately how many half-lives is this?

anonymous · Answer

2. How much carbon-14 is present in a 58,000 year old skeleton that originally contained 456 g of carbon-14?

thesmartone · Answer

Use this formula to calculate half-lives:

$\sf\Large A = A_0 \times 2^{\frac{-t}{h}}$

$\sf A$ is the final amount.
$\sf A_0$ is the Initial Amount
$\sf t$ is the Time
$\sf h$ is the Half-Life

anonymous · Answer

I know the formula, but I don't know where I have to put the 456 g??

anonymous · Answer

@january123

aaronq · Answer

$\sf \color{green}{>originally~ contained~ 456~ g}$

$\sf \color{green}{>originally}$

i.e. initial amount, $\sf A_o$

aaronq · Answer

I also think that formula i wrong, it's supposed to be: 

$\huge \sf A=A_0*\dfrac{1}{2}^{\large \dfrac{-t}{h}}$

thesmartone · Answer

My bad, aaronq has the correct formula (: