Question 9

A 50 litre mixture of water and alcohol contains 10% alcohol. How much more alcohol must be added to make the strength of alcohol 40% in the new mixture?

Solution

Quantity of alcohol in 50 litres mixture = $$\frac{10}{100}\times50=5$$ litres

Let $$x$$ litres of alcohol is added,

=> $$x+5=\frac{40}{100}\times(x+50)$$

=> $$x+5=\frac{2}{5}\times(x+50)$$

=> $$5x+25=2x+100$$

=> $$5x-2x=100-25$$

=> $$3x=75$$

=> $$x=\frac{75}{3}=25$$

$$\therefore$$ 25 litres alcohol must be added to make the strength of alcohol 40% in the new mixture.

=> Ans - (A)

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: