A certain store sells all maps at one price and all books at another price. On Monday the store sold 12 maps and 10 books for a total of Rs.38.00, and on Tuesday the store sold 20 maps and 15 books for a total of Rs 60.00. At this store, how much less does a map sell for than a book?
12m+10b = 38;
20m+15b=60;
Solving these we get m=1.5; b=2;
Difference = Rs 0.5