1. P1 : P2 = C1 × T1 : C2 × T2; C1 = Partner 1's Capital. T1 = Time period for which Partner 1 contributed his capital. P2 = Partner 2's Profit.

2. Let partner X be an active partner within the partnership for a given time of X and similarly, let partner Y be an active partner within the partnership business for the time of y. Therefore, the formula to calculate the profit-sharing ratio is (X's profit share)/(Y's profit share) = a(x)/b(y).

3. Partnership is based on three points, first is time, second is investment and the third one is profit. Here, Profit ∝ investment and Profit ∝ time. So, ratio of profit is directly proportional to the product of investment and time.