Question

A lending library has a fixed per day charge for the first three days and an additional charge for each day thereafter. Arushi paid Rs. 27 for a book kept for seven days. The fixed charges are Rs. x per day and additional charges are Rs. y per day. Write the linear equation representing the above information.

Answer 1

Given that, a library has a fixed per day charge for the first three days and an additional charge for each day thereafter.

The fixed charges are $Rs.x$ per day and the additional charges are $Rs.y$ per day.

Also, Arushi paid $Rs.27$ for a book she kept for $7$ days.

Since the book was kept for $7$ days, fixed charges will be applicable for each of the first three days and an additional charge of $Rs.y$ per day for the remaining days.

Hence, per day charges after three days $=Rs.(x+y)$.

$\therefore 3x+(7-3)(x+y)=27$

$\Rightarrow 3x+4x+4y=27$

$\Rightarrow 7x+4y=27$

Hence, the linear equation representing the given information is $7x+4y=27$.