Question

In a mixture of 360 liters, the ratio of cement and water is 5:4. If the ratio is to be 5:7, then what would be the quantity of water to be altered?

Answer 1

Answer:

The required quantity of water is 120 litres

Step-by-step explanation:

Quantity of mixture = 360 litres

Ratio of cement and water in the mixture is 5:4

Quantity of cement in the mixtrue = 5k

Quantity of water in the mixture = 4k

This implies,

5k+4k=360

9k =360

$k=\frac{360}{9}=40$

Quantity of cement in the mixtrue = 5(40)=200 litres

Quantity of water in the mixture = 4(40)=160 litres

Let 'x' be the quantity of water to be added to make the mixture ratio 5:7

Then,

$200 : (160+x) = 5:7\\\\\frac{200}{160+x}=\frac{5}{7}\\\\1400=800+5x\\\\5x=600\\\\x=120$

The required quantity of water is 120 litres

Answer 2

Answer:

120 Litre water

Step-by-step explanation:

In a mixture of 360 liters, the ratio of cement and water is 5:4. If the ratio is to be 5:7, then what would be the quantity of water to be altered?

Mixture = 360 litre

Cement : water = 5: 4

Cement = 5/(5+4)  * 360 = 200

Water = 4/(5+4) * 360 = 160

Let say x litre water added to have ratio of 5:7

Cement = 200

Water = 160 + x

Total = 360 + x

200/ (160 + x) = 5/7

=> 1400 = 800 + 5x

=> 5x = 600

=> x = 120

120 Litre water to be added