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.

m∠a is 90°

m∠b is 40°

10 - 75

step-by-step explanation:

there's nothing attached so it's most likely anything in that range.