Three partners shared a profit in a business in the ratio of 2 : 3 : 6. They had partnered for 12 months, 9 months and 6 months respectively. The ratio of their investment is :

1 : 2 : 6 1 : 2 : 4 2 : 6 : 1 2 : 1 : 4

1 : 2 : 6