Question

You have 160 grams of a substance. If it has a half life of 8 days, how much will be left after 32 days?

Answer 1

If the half-life of the substance is 8 days, then after each 8-day period, half of the substance will decay. So after 8 days, you will have 80 grams left (half of the initial amount), and after another 8 days (for a total of 16 days), you will have 40 grams left (half of the 80 grams remaining).After another 8 days (for a total of 24 days), you will have 20 grams left (half of the 40 grams remaining). Finally, after another 8 days (for a total of 32 days), you will have 10 grams left (half of the 20 grams remaining).Therefore, after 32 days, you will have 10 grams of the substance left.

Answer 2

If a substance has a half-life of 8 days, it means that after every 8 days, the amount of substance remaining will be half of the previous amount.

So, after 8 days, the amount remaining will be:

160 / 2 = 80 grams

After another 8 days (total of 16 days), the amount remaining will be:

80 / 2 = 40 grams

After another 8 days (total of 24 days), the amount remaining will be:

40 / 2 = 20 grams

Finally, after another 8 days (total of 32 days), the amount remaining will be:

20 / 2 = 10 grams

Therefore, after 32 days, there will be 10 grams of the substance left.

Explanation: