Let the firm has x number or large vans and y number of small vans. From the gives, information we have following corresponding constraint table.
Thus, we see that objective function for minimum cost is Z=400x+200y.
Subject to constraints `200x+80y ge 2000["pakage constranit"]`
`Rightarrow 5x+2y ge 30....(i)`
and `400x+200y le 3000["cost constraint"]`
`Rightarrow 2x+y le 15 ...(ii)`
and `x le y ..["van constraint"]...(iii)`
and `x ge 0, y ge 0 ["non negative constraints"]...(iv)`
Thus, required LPP to minimise cost is minimise `Z=400x+200y, "subject to " 5x+2y ge 30`
`2x+y le 15`
`x le y`
`x ge 0, y ge 0`