The shaded region in the following figure represents the solution set for a certain linear programming problem. The linear constraints for this region are given by:

The maximum value of $Z=10 x+25 y$ subject to $0 \leq x \leq 3, 0 \leq y \leq 3, x+y \leq 5, x \geq 0, y \geq 0$ is

The feasible region of the $L$.$P$.$P$. (Linear Programming Problem) to maximize $z = 70x + 50y$ subject to the constraints $8x + 5y \leq 60$,$4x + 5y \leq 40$ and $x \geq 0, y \geq 0$ is:

$A$ company makes $3$ models of calculators: $A, B$ and $C$ at factory $I$ and factory $II.$ The company has orders for at least $6400$ calculators of model $A, 4000$ calculators of model $B$ and $4800$ calculators of model $C.$ At factory $I, 50$ calculators of model $A, 50$ of model $B$ and $30$ of model $C$ are made every day; at factory $II, 40$ calculators of model $A, 20$ of model $B$ and $40$ of model $C$ are made every day. It costs $Rs. 12000$ and $Rs. 15000$ each day to operate factory $I$ and $II,$ respectively. Find the number of days each factory should operate to minimize the operating costs and still meet the demand.

The maximum value of $Z = 4x + 5y$, subject to the constraints $3x + y \leq 15$, $3x + 4y \leq 24$, $x \geq 0$, $y \geq 0$ is

$A$ production unit makes a special type of metal chip by combining copper and brass. The standard weight of the chip must be at least $5 \text{ gms}$. The basic ingredients,i.e.,copper and brass,cost $₹8$ and $₹5$ per $\text{gm}$ respectively. Durability considerations dictate that the metal chip must not contain more than $4 \text{ gms}$ of brass and should contain a minimum of $2 \text{ gms}$ of copper. Then,the minimum cost of the metal chip satisfying the above conditions is: