Solution A and solution B are solutions of alcohol in water. The mixture of 100 ml of solution A and 150 ml of solution B has a concentration of 20%. If the ratio of concentration of A and B is 3: 8, find the concentration of solution A.

Hi Let concentration of A be a% and B be b % Now a:b =3:8 Now when 100ml of A and 150 ml of B will have total 250 ml solution and 250*0.2=50ml alcohol Now adding alcohol concentrations : a+3b/2 =50 using a:b=3:8 we get a=10 so concentration of a will be 10%