# science

posted by
**courtney**
.

if a egyptian mummy has 61% carbon-14 how long ago was it buried?

Take a 100 g initial sample. Now there are 61 g C-14.

Use ln(No/N) = kt

where No = 100

N = 61

You will need k and you may obtain that from k = 0.693/t_{1/2}.

Look up t_{1/2} and substitute in that equation to find k, then substitute k in the first equation I listed. Post your work if you get stuck.