470 liters of a mixture of milk and water contains 5% of water. A mischievous boy added some water in the mixture and now there is 6% water in the new mixture. Find the quantity of water added by the boy in the mixture.

5 litres

Let x liter water be added

Now, according to question,

Milk: 95% of 470 = 94% of (470 + x)

(95 × 470) = (94 × 470) + 94x

(95 × 470) - (94 × 470) = 94x

94x = 470

x = 5 liter

Therefore, 5 liter must be added to make water 6% in the new mixture.