The cost of a book is `Rs(3x-5y)` Find the cost of such `(3x-5y)` books.If `x=8` and `y=2` then find the cost of the books.

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

If the cost of a book is Rs.25.75 ,find the cost of 24 such books.

The cost of 5 books is Rs. 40. What is the cost of 7 books?

14 books cost Rs 133, then find the cost of 20 books.

If cost of 5 bags is Rs5250, then find the cost of 3 such bags.

If 8 pens cost Rs. w, find the cost of 5 such pens.

The total cost of 6 books and 7 pens is 79 rupees and the total cost of 7 books and 5 pens is 77 rupees.Find the cost of 1 book and 2 pens.

The cost of 4 Books and 7 Registers is Rs. 1250. What is the cost of 12 books and 21 Registers?