In a mixture of 110 litre the ratio of water and milk is 4 : 7 respectively. How much water must be added to make the ratio of water and milk as 8 : 7 respectively?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 40 liters.
In the original mixture, the total amount is 110 liters, and the ratio of water to milk is 4:7. The total ratio parts are:
⇒ 4 + 7 = 11 parts
The amount of water in the mixture is:
⇒Water = 4 / 11 × 110 = 40 liters
The amount of milk in the mixture is:
⇒ Milk = 7 / 11 × 110 = 70 liters
After adding ( x ) liters of water, the total amount of water will be:
⇒ New water = 40 + x liters
the ratio of water to milk to be 8:7,
⇒ 40 + x / 70 = 8 / 7
⇒ 7(40 + x) = 8 × 70
⇒ 280 + 7x = 560
⇒ 7x = 560 - 280
⇒ 7x = 280
⇒ x = 280 / 7= 40.
40 liters of water must be added to the mixture to make the ratio of water to milk 8:7.