B. The total because your adding. By adding something you will get the total!
Answer:
i hope this helps
Step-by-step explanation:
download the image below it is the answer to your problem
Answer: There will be 0.04 grams will be left in the sample after 20 years.
Step-by-step explanation:
Since we have given that

Here, Initial amount of radioactive substance = 400 grams
We need to find the amount of substance that will be left in the sample after 20 years.
So, t = 20 years
So, it becomes,

Hence, there will be 0.04 grams will be left in the sample after 20 years.
Answer:
63 days
Step-by-step explanation:
Answer:
20.3cm^2
Step-by-step explanation:
Bullseye has a circular shape. So area of a bulleyse = Pi x (radius) ^2
Díameter is 2 inches = 5. 08cm
But radius = diameter /2
Radius = 5.08cm /2
Radius = 2.54cm
Hence Area of bulleyse = 3.14 x (2.54) ^2
= 3.14 x 6. 451 cm^2
= 20.256 cm^2
=20.3cm^2 (to nearest tenth)