Question 313236
12mL of a 10% ,
5 mL of 80% 
20mL of a 45% 
..
total quantity of mixture = 37 ml of x%
..
concentration equation 
0.1*12 +0.8*5+0.45*20 = 0.08x*37
1.2+4+9= 2.96x
14.2= 2.96x
x= 14.2/2.96
x= 4.8 


% = 38