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.

Answer

₹ 15, ₹ 3 per day

Explanation

Let the fixed charge be ₹ x and charge for each extra day be ₹ y .
Then, ` x + ( 7- 3)y = 27 " " `… (i)
and, ` x + ( 5 -3 ) y = 21 rArr x + 2y = 21" " `… (ii)