The answer is 5.21. You just divide 125 24
Answer:
i.e. 393650 kg.
Step-by-step explanation:
Given that Radium-226 is a radioactive substance with an annual decay rate of 0.04 %
Let the year 1937 be 0 year
Initially population was = 400,000 kg
Since decay rate is 0.04% per year after t years population would be
![P(t) = 400,000 (1-0.0004)^t](https://tex.z-dn.net/?f=P%28t%29%20%3D%20400%2C000%20%281-0.0004%29%5Et)
=![400,000*0.9996^t](https://tex.z-dn.net/?f=400%2C000%2A0.9996%5Et)
In 2017, t = 40 years (i.e. years lapsed form 1937)
Hence population
= ![P(40) = 400,000 (0.9996)^{40} \\=393649.66](https://tex.z-dn.net/?f=P%2840%29%20%3D%20400%2C000%20%280.9996%29%5E%7B40%7D%20%5C%5C%3D393649.66)
i.e. 393650 kg.