150 ml of 30% sulphuric acid was added to approximate 400 ml of 12% sulphuric acid solution. Find the approximate concentration of the acid in the mixture?	Select the correct option
A) 1 / 2
B) 1 / 3
C) 1 / 4
D) 1 / 6
E) 1 / 5

Rationale: 150 ml solution contains 45 ml sulphuric acid 400 ml solution contains 48 ml sulphuric acid adding 550 ml solution contains 93 ml sulphuric acid 93 / 550 ≈ 90 / 540 = 1 / 6 answer is d
Answer: D