Question

Two solutions of 90% and 97% purity are mixed resulting in 21 litres of a mixture of 94% purity. How much is the quantity of the first solution in the resulting mixture?

Options

• 15 liters

• 12 liters

• 9 liters

• 6 liters

Answer 1

9 liters

Explanation:

By alligation rule

   .............(94 − 90: 97 − 94)
                                           3: 4       

∴ Quantity of the first solution in 21 litres of Mixture

`=3xx21/7`

= 9 litres.