Answer:
5 : 2
Step-by-step explanation:
sum the parts of the ratio, 7 + 2 = 9 parts
Divide the quantity by 9 to find the value of one part of the ratio
45 litres ÷ 9 = 5 litres ← value of 1 part of the ratio , then
7 parts = 7 × 5 = 35 litres
2 parts = 2 × 5 = 10 litres
In 45 litres there is 35 litres of milk and 10 litres of water
Adding 4 litres of water gives
35 : 14 = 5 : 2
