BUSINESS for N MONTHS. Then, A : B = (2250 X 12) : (2700 x N) 2 : 1 = (27000 : 2700N) = (10 : N) 10/N = 2/1 [ ∵ Ratio of profit is 2 : 1] 2N = 10 N = 10/2 = 5Clearly, B joined after (12 - 5) = 7 months.