Hello chowdarymahima409,

Well, If a Solution has X ppm concentration then it means it has total X gms of solute dissolved in 10^6 ml of solution or 10^3 Lts of solutions(where X=100), so if want to know the amount of solute , in 100 gms of solution, we have 100/d ml volume of solution where d is the density of solution(gm/ml). So, we have Xgms of solute in 10^6 ml of Solution => X/(10^6) gms of solute in 1 ml of solution => {X/(10^6)}*(100/d) gms of solute in 100/d ml of volume of solution or 100 gm of solutions.

Here, X=100, So you ans is {100/10^6}*100/d i.e. d/100 gm of solute, and we need to know the d i.e. density of solution to get the answer... in case of water we have 0.01gms of solute...

Hope this helps, and feel free to ask any further query...