 
       
      
    In a mixture of 45 litres, the ratio of milk and water is 3 : 2, How much water must be added to make the ratio 9 : 11?
25 litres
 
                
                  45 L
M= 3/5 x 45 = 27 L
W = 18 L
27 / 45 + X = 11/ 20
540 = 495 + 11X
11x= 55
X = 5L
