If 5 gross clay boxes cost ₹21,600 , find the cost of 9 such clay boxes . ( Hint :- 1 gross = 12 dozen = 144 )

If the cost of 5 ice creams is Rs. 15, find the cost of 9 ice creams.

The cost of 12 books is Rs. 144. Find the cost of 18 books.

The cost of 1 dozen pens is Rs. 24. Find the cost of 30 pens.

The cost of 5 pens and 8 pencils is ₹ 120, while the cost of 8 pens and 5 pencils is ₹ 153. Find the cost of 1 pen and that of 1 pencil.

The cost of 4 pens and 4 pencils boxes is Rs. 100. Three times the cost of a pen is Rs. 15 more than the cost of a pencil box. Form the pair of linear equations for the above situation. Find the cost of a pen.

The cost of 3 oranges and 12 apples is Rs. 9.60 and the cost of 5 oranges and 7 apples is Rs. 6.90. Find the cost of apples per dozen.

Cost of a dozen red pens is Rs. 108 and cost of 9 black pens is Rs.54. Find the ratio of cost of a red pen to the cost of a black pen.

Shanti Sweet Stall was placing an order for making carboard boxes for packing their sweets. Two sizes of boxes were required. The bigger of dimensions 25cm xx20cm xx5cm and the smaller of dimensions 15cm xx 12cm xx5cm . For all the overlaps, 5% of the total surface area is required extra. If the cost of the carboard is Rs. 4 for 1000 cm^(2) , find the cost of carboard required for supplying 250 boxes of each kind.

The total cost of a score of apples and a dozen of oranges is greater than or equal to ₹ 420. The cost of each apple cannot exceed ₹ 15. Find the minimum possible cost of each orange ( in ₹) ( 1 score = 20).