Question

The concentration of petrol in three different mixtures (of petrol and kerosene) is 1/2,3/5 and 4/5 respectively. If 2 litres, 3 litres and 1 litre are taken from these three different vessels and mixed, what is the ratio of petrol and kerosene in the new mixture?

• A. 4 : 5
• B. 3 : 2
• C. 3 : 5
• D. 2 : 3

Answer 1

Answer: (B)

3 : 2

Answer 2

Quantity of Petrol in the mixture,

$=\frac{1}{2}×2+\frac{2}{5}×3+\frac{4}{5}×1$

$=1+\frac{9+4}{5}$

$=\frac{18}{5}$

Quantity of kerosene in the mixture,

$=\frac{1}{2}×2+\frac{2}{5}×3+\frac{1}{5}×1$

$=1+\frac{6+1}{5}$

$=\frac{12}{5}$

Ratio of petrol and kerosene in the mixture,

$=\frac{18}{5}:\frac{12}{5}$

$=3:2$

Hence, option B is the correct answer.The correct option is (B): 3 : 2