We see:

\(\sqrt{100}=10;\sqrt{999}>31\)

So the numbers from 10 to 31 is the square root of three-digit positive intergers 

So there are \(31-10+1=22\) numbers

We have:

100 = 10²

999 = \(3\sqrt{111}\) > 31

=> The numbers from 10 to 31 i the ssquare root of three-digit positive intergers.

So there are:

31 - 10 + 1 = 22 numbers

Ans: