Answer:
The bones were 12,485 years old at the time they were discovered.
Step-by-step explanation:
Amount of the element:
The amount of the element after t years is given by the following equation, considering the decay rate proportional to the amount present:

In which A(0) is the initial amount and k is the decay rate, as a decimal.
The radioactive element carbon-14 has a half-life of 5750 years.
This means that
, and we use this to find k. So







So

A scientist determined that the bones from a mastodon had lost 77.8 % of their carbon-14. How old were the bones at the time they were discovered?
Had 100 - 77.8 = 22.2% remaining, so this is t for which:

Then






The bones were 12,485 years old at the time they were discovered.
$30 because if you add 30 to those numbers it would give you the next months amount.
Answer:
2 11/14 squared feet
Step-by-step explanation:
Area of a rectangle = length x width
Give length = 3 1/4 and
Width = 3/4
Therefore,
Area = 3 1/4 x 3/4
Change the mixed size fraction to an improperly fraction
We have A = 13/4 x 3/4
39/14
2 11/14 squared feet
He will burn 225 calories. if you divide 150/20 it will equal 7.5 then multiply 7.5 by 30 and you’ll get 225
Subtracting the weight of the smaller brick from the larger gives us the weight difference:
4 3/8 lb - 2 1/3 lb. The two denominators are 8 and 3 respectively, resulting in an LCD of 24. Thus, our problem becomes:
4 9/24 - 2 8/24, which equals 2 1/24 lb. The weight difference is 2 1/24 lb.