After releasing of radioactive material into. The atnosphere from. A nuclear. Powe plant in a country in 1988, the hay in that country was contaminayed by radioactive. Isotope remains, how long did the famers need to. Wait to use this hay

the question is incomplete, so I looked for a similar one:

After the release of radioactive material into the atmosphere  from a nuclear power plant, the hay was contaminated by iodine  131 ( half-life, 8 days). If it is all right to feed the hay to cows  when 10% of the iodine 131 remains, how long did the farmers  need to wait to use this hay?

iodine's half life (we are given x, we need to find b):

0.5A₀ = A₀eᵇˣ

x = 8 days

we eliminate A₀ from both sides

0.5 = eᵇ⁸

ln 0.5 = ln eᵇ⁸

-0.69315 = b8

b = -0.69315 / 8 = -0.08664

since the farmers need to wait until only 10% of the iodine remains (we already calculated b, now we need to find x):

0.1A₀ = A₀eᵇˣ

0.1 = eᵇˣ

ln 0.1 = bx

where b = -0.08664

x = ln 0.1 / -0.08664  = -2.302585 / -0.08664  = 26.58 days

x + 4/7

step-by-step explanation:

use cymath