Percentage

Vedic Maths trick to Find Percentage.

How many L of pure alcohol must be added to '40' L of '3%' solution of alcohol and water to increase it to a '9%' solution.

Amount of alcohol in 20 L solution = [ 3 / 100 * 40] % = 1.2 L

Let 'Y' L of pure alcohol to be added

1.2 + Y / 40 + Y = 9 / 100

120 + 100Y = 360 + 9Y

100Y - 9Y = 360 - 120

91Y = 240

Y = 240 / 91

Y = 240 / 91 L

Y = 240 / 91 L

240 / 91 L of pure alcohol must be added.