A tank with rectangular base and rectangular sides open at the top is to be constructed so that its depth is 3 m and volume is 75 `"m"^3`. If building of tank costs Rs. 100 per square metre for the base and Rs. 50 per square metre for the sides, find the cost of least expensive tank.

A tank with rectangular base and rectangular sides, open at the top is to be constructed so that its depth is 2m and volume is 8 m^3 . If building of tank costs Rs. 70 per sq. metre for the base and Rs. 45 per sq. metre for sides, what is the cost of least expensive tank?

Find the cost of fencing a square park of side 300m at the rate of Rs. 20 per metre.

One side of a square plot is 250m, find the cost of levelling it at the rate of Rs. 2 per square metre.

The total cost of flooring a room at Rs. 8.50 per square metre is Rs. 510. If the length of the room is 8 metres, find its breadth.

The volume of a closed square based rectangular box is 1000 cubic metre. The cost of constructing the base is 15 paise per square metre and the cost of constructing the top is 25 paise per square metre. The cost of constructing its sides is 20 paise per square metre and the cost of constructing the box is Rs. 3.Find the dimensions of box for minimum cost of construction.

One side of a square field is 179 m. Find the cost of raising a lawn on the field at the rate of Rs 1.50 per square metre.

The cost of papering the walls of a room 12 m long at the rate of Rs. 13.50 per square metre is Rs. 3402 and the cost of matting the floor at Rs. 9.50 per square metre is Rs. 1026. Find the height of the room.

A rectangular grassy lawn measuring 30m by 28 m is to be surrounded externally by a path which is 2 m wide. Find the cost of levelling the path at the rate of Rs 5 per square metre.

A rectangular grassy lawn measuring 30m by 28 m is to be surrounded externally by a path which is 2 m wide. Find the cost of levelling the path at the rate of Rs 5 per square metre.

If a cloth costs Rs 715 1/4 per metre, find the cost of 3 2/5 metres of this cloth.