Question

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 1

Let the fixed charge and the charge for each extra day be ‘a’and ‘b’ respectively.

Given, 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

⇒ a + 4b = 27 -------- (1)

Susy paid Rs 21 for the book she kept for five days

⇒ a + 2b = 21 --------- (2)

Subtracting eq2 from eq1

⇒ 2b = 6

⇒ b = 3

Putting this value in eq(1), we get

⇒ a + 4(3) = 2

⇒ a = 27 - 12

⇒ a = 15

Therefore, fixed charge,

a = 15

Rupees and charge thereafter,

b = 3

Rupees per day

⇒ a = Rs. 15