what is the dilution factor if you make a 1/10 dilution and then make another 1/10 dilution from the first dilution?

Question

So if I start with a stock tube of 100ul and take 10ul + 90ul water to make a 1/10 dilution that is my 1/10 dilution of the stock. Now if I make another dilution from my 1/10 by taking 0ul + 90ul water again is that a 1/100 dilution of my original stock?

Answer 1

Yes it is.  You are diluting to 1/10 of something that is already diluted to 1/10, so you are diluting to (1/10)² = 1/100.