The ratio of water and milk in a 30 liter mixture is 7 : 3. Find the quantity of water to be added to the mixture in order to make this ratio 6 : 1.

ratio 7 = water
ratio 3 = milk
total ratio (10) = 30 liters
so, 30--------------10 (for milk)
m -------------- 3 (cross multiply)
30 x 3 = m(10)
milk=9
water =21 liters

let x amount of water added to mixture and new ratio is 6 : 1
so, water milk
21+x : 9
6 : 1
(21+x) 1 = 6 x 9
21+x = 54
x=33 ANSWER

The previous ratio is 7:3 now,
Quantity of water in mixture= 30*7/10=21
Quantity of milk in mixture=30*3/10=9
The new ratio is 6:1
So, let water added=x
According to new ratio,
(21+x)/9=6/1
21+x=54
x=33
The extra water added is 33 liters.

when 1 liter of water is added to a mixture of milk and water,the new mixture contains 20% milk.when 1 liter of milk is added to the new mixture the resulting mixture contains 33 % milk.the % of milk in the original mixture was?

i dont understand this solution