Question

A mixture of 40 litres of milk and water contains l0% of water. How much water should be added to this mixture so that the new, mixture contains 20% water? A. 4 litres b. 5 litres c. 7.5 litres d. None of the above

Answer 1

Answer: b. 5 litres

since 10% of 40 l is 4 l.

therefore, 20% of 40+5= 9

9 l - 4 l = 5 l

Answer 2

40 litre milk added 10 %water
=40 10 %
=40 1% = 40/100 = 0.4
=40 10 %= 0.4 × 10 = 4 litre
this question answer is a. 4 litre