Carbon 14 has a half life of 5730 years. After 17190 years, 1/8 of the carbon in a sample will be left. If 5 grams of carbon are left after 17190 years, how

Question

How much was in the original sample?

Answer 1

The half life of carbon is extra information in this problem, and is not needed.

 

The problem is asking a simple question:

 

5 grams are left.

5 grams is 1/8 of the original amount.

What was the original amount?

 

In other words, 1/8 * X = 5

Solve for X.

 

Multiply both sides by 8:

x = 5 * 8 = 40

 

Therefore, the original sample had 40 grams.