A lending library has a fixed charge for the first three days and an additional charge for each day thereafter. Mona paid Rs. 27 for a book kept for 7 days, while Tanvy paid Rs. 21 for the book she kept for 5 days. Find the fixed charge and the charge for each extra day.

Let the fixed charge and the charge for each extra day be x and y respectively.


According to question -


x + 4y = 27


and,


x + 2y = 21


Subtracting equation (2) from (1), we get -


y = 3


Substituting the value of y in (2), we get -


x = 15


Thus, Fixed Charge = 15 and the charge for each extra day = Rs. 3 per day.


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