Half life period of `""_(53)I""^(125)` is 60 days. Percentage of radioactivity preent after 180 days is a).5 b).75 c).36 d).125

Explanation

To solve the problem of finding the percentage of radioactivity present after 180 days for iodine-125, we can follow these steps:

### Step 1: Understand the Half-Life
The half-life of iodine-125 is given as 60 days. This means that every 60 days, half of the original amount of iodine-125 will remain.

### Step 2: Calculate the Number of Half-Lives
To find out how many half-lives fit into 180 days, we divide 180 by the half-life (60 days):
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