Question

A lending library has fixed charge for the first three days and an additional charges for each day thereafter. John paid ₹ 27 for a book kept for seven days. If the fixed charges be ₹ x and subsequent per day charges be ₹ y; then write the linear equation representing the above information and draw the graph of the same. From the graph if the fixed charge is ₹ 7, find the subsequent per day charge. And if the per day charge is ₹ 4, find the fixed charge, (charge is ₹7)

Answer 1

John kept a book for 7 days. He paid ₹ 27 

For first three days = ₹ x (fixed) 

For the last four days = ₹ 4y (? y for a day) 

By problem x + 4y = 27

x	3	11	7
y	6	4	5

When x = 7 then y = 5 

When y = 4 then x = 11