I have 5 test tubes. put .4ml of saline into tube 1 and .25ml into each remaining tube. Put .1ml of serum into tube 1, mixwell and transfer .25ml to tube to. mix tube 2 and transfer .25ml to tube 3 and so on to tube 5 and discard .25ml from tube 5. add .1ml of cells to each tube. the final delutions are 1:7 through 1:224. I need to know how to solve mathmatically what the delutions are for tubes 2-5 and just cant figure it out.