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 the fixed charge for first three days and each day charge thereafter be Rs x and Rs y respectively.
According to the question,
x + 4y = 27 ....(1)
x + 2y = 21 ....(2)
Subtracting equation (2) from equation (1), we obtain:
2y = 6
y = 3
Subtracting the value of y in equation (1), we obtain
x + 12 = 27
x = 15
Hence, the fixed charge is Rs 15 and the charge per day is Rs 3