The <em>echo</em> number 20222022202220222022 is the <em>perfect</em> square of 4496890281.
<h3>What echo number is a perfect square</h3>
An <em>echo</em> number has a <em>perfect</em> square if its square root is also a <em>natural</em> number. After some iterations we found that <em>echo</em> number 20222022202220222022 is a <em>perfect</em> square:

The <em>echo</em> number 20222022202220222022 is the <em>perfect</em> square of 4496890281. 
To learn more on natural numbers, we kindly invite to check this verified question: brainly.com/question/17429689
I believe the answer would b ( B) 1/3
Hope this helps!
This could be wrong but the remaining pieces he can cut is 3 because if you divide 400 with 8 , it’s 35 as the answer, so then subtract 35 with 15 till you can subtract 15 from it