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

let fixed charge = Rs. x .... additional charge = Rs. y ....

For Saritha :- Rs (x + 4y) = Rs. 27

----> x + 4y = 27 ..... (I) ....

For Susy :- Rs. (x + 2y) = Rs. 21

----> x + 2y = 21 .... (II) ...

Solving both equations :-

2y = 6 --- > y = 3 .....

x = 21 - 2y [from (II)] ...

----> x = 21 - 6 = 15 ....

Hence, fixed charge for first three days = Rs. 15 ..... (ans) ...

and additional charge for each day = Rs. 3 .... (ans) ...

Hope this helps !!!

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