A container contains a dry mixture of sand and stones. Mass of sand and stones in the container is in the ratio 1:3. If 12 kg sand is added to the container, the ratio of masses of sand and stones becomes 5:3. Originally, how much more was the mass of stones than sand in the container? Pick one:
A) 12
B) 9
C) 6
D) 3
E) 1
Suppose originally the mass of sand in the container was x. So the mass of stones, originally, would be 3x because mass of sand and stones in the container is in the ratio 1:3.   If 12 kg sand is added, mass of sand becomes x + 12, and the mass of stones remains unchanged. But now the ratio of the mass of sand and stones is 5:3.   This means,   (x + 12)/3x = 5/3, which gives x = 3.   So originally, there was 3 kg sand and 9 kg stones.   So, the mass of stones was 6 kg more than the mass of sand.   Ans 6
<result>C</result>
A container contains a dry mixture of sand and stones. Mass of sand and stones in the container is in the ratio 1:3. If 12 kg sand is added to the container, the ratio of masses of sand and stones becomes 5:3. Originally, how much more was the mass of stones than sand in the container?