Dilip, Ram and Avtar started a shop by investing Rs. 2700, Rs. 8100 and Rs. 7200 respectively. At the end of one year, the profit earned was distributed. If Ram's share was Rs. 3600, what was their total profit ?

$$\eqalign{ & {\text{Dilip}}:{\text{Ram}}:{\text{Avtar}} \cr & = 2700:8100:7200 \cr & = 3:9:8 \cr & {\text{Let the total profit be Rs}}.\,x \cr & {\text{Then, Ram's share}} \cr & = {\text{Rs}}{\text{.}}\,\left( {\frac{9}{{20}}x} \right) \cr & \therefore \frac{9}{{20}}x = 3600 \cr & \Rightarrow x = \left( {\frac{{3600 \times 20}}{9}} \right) \cr & \Rightarrow x = 8000 \cr & {\text{Hence,}} \cr & {\text{Total profit}} = {\text{Rs}}{\text{. 8000}} \cr} $$