A radioactive material has a half-life of 15 days if you start with 160 mg after how long will they be 5mg left?

  75 days

Step-by-step explanation:

The multiplier each day is ...

  (1/2)^(t/15)

Then we want to find t such that ...

  5 = 160·(1/2)^(t/15) . . . . . . 5 mg are left after t days

  5/160 = (1/2)^(t/15) . . . . . . divide by 160

  1/32 = (1/2)^5 = (1/2)^(t/15) . . . . rewrite the left side

Equating exponents (equivalent to taking logs), we get ...

  5 = t/15

  5·15 = 75 = t . . . . . multiply by 15 to find t

After 75 days, there will be 5 mg left.

answer: 1,380

step-by-step explanation:

1: you turn %15 into a decimal by moving the decimal point two places to the left.

2: and then you multiply .15 by 1,200 , which will get you 180.00

3: from there you will add 180 to 1,200

4: which will get you 1,380

hope it *im kind of slow so idk if my answer is right*

idk

step-by-step explanation: