Total cost of 45 books and 65 copies is 1290 and that of 65 books and 45 copies is 1500. What will be cost of 1 book?

Question

The cost of a book and a notebook are 100 rupee and 40 rupee respectively.
If a shopkeeper gives a discount of 10% and 4% in the two items respectively.
Then what is the total cost of 10 books and 4 notebooks?

Answer 1

b= cost of 1 book , c=cost of 1 copy

9b + 13c = 258 ;;; 13b + 9c = 300 ;;

solving we get b=Rs. 17.93