What is amu of 99 % h-1, .2% h-1 and .8% h-3

The average atomic mass of your mixture is 1.03 u .

The average atomic mass of H is the weighted average of the atomic masses of its isotopes.  

We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its % abundance).  

Thus,  

0.99    × 1.01 u = 0.998 u

0.002 × 2.01 u = 0.004 u

0.008 × 3.02 u = 0.024 u

            TOTAL =  1.03   u

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.