Two bodies of different masses are dropped simultaneously from the top of a tower. If air resistance is same on both of them, 

If air resistance is R and mass of body is 'm', then acceleration 

$\mathrm{a}=\frac{\mathrm{mg}-\mathrm{R}}{\mathrm{m}}=\mathrm{g}-\frac{\mathrm{R}}{\mathrm{m}}$

Therefore acceleration 'a' is more for heavier body. 

Since time of fall is given by $\mathrm{t}=\sqrt{\frac{2\mathrm{h}}{\mathrm{a}}}$.

The heavier body reaches the ground first.