Get expert insights and reliable answers to your questions on IDNLearn.com. Ask your questions and receive comprehensive and trustworthy answers from our experienced community of professionals.

A lending library has a fixed charge for the first three days and an additional charge for each day thereafter. Saritha paid ₹27 for a book kept for seven days, while Susy paid ₹21 for the book she kept for five days. Find the fixed charge and the charge for each extra day.​​