Question

14. A 90 liter mixture of milk and water contains 10%
water. How much water must be added to make water
20% in the mixture?
324
300
325
320​

Answer 1

Answer:

I think it is 325

Step-by-step explanation:

I think it will be helpful

Answer 2

11.25 Litres of water must be added to make water 20% in the mixture

A 90 Litre mixture of milk and water contains 10% water.

We have to find the amount of water must be added to make water 20% in the mixture.

A/C to question, initially milk and water mixture contains 10% water.

it means, amount of water = 10 % of 90 = 9 litres

amount of milk = 90 - 10 = 81 litres

Let x litres of water must be added to make water 20% in the mixture.

we know, milk remains constant in both cases.

so, initial amount of milk = final amount of milk

⇒81 litres = 80% of final mixture

⇒81 = 4/5 (90 + x)

⇒405 = 360 + 4x

⇒x = 45/4 = 11.25 Litres

Therefore the amount of water must be added to mixture is 11.25 litres.

To verify :

total amount of milk in final mixture = 9 + 11.25 = 20.25

total amount of final mixture = 90 + 11.25 = 101.25

∴ percentage of milk in mixture = amount of milk/amount of mixture × 100

= 20.25/101.25 × 100

= 2025/101.25

= 20 % [ hence our answer is correct].