If you have 10 grams of a substance Tha. t decays with a half-life of 14 days, then how much will you have after 42 days?

3.13g

6.25g

1.25g

2.50g

The answer would be 1.25g

Since you have 10g of a substance, you would need to half your substance by doing this: 42/14=3

Once doing this you would half your substance 3 times like so:

10/2=5

5/2=2.5

2.5/2=1.25