One of the most important and exam oriented question from linear equations in two variables in which we have the fixed rate and rate for each extra day if a lending library has a fixed charge for the first three days and 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.

Kindly solve the above problem by using the properties of linear equations

RS Aggarwal, Class 10, chapter 3E, question no 47

## Let the fixed charge be Rs. x

and the extra charge be Rs. y

x+4y=27⟶(i)

x+2y=21⟶(ii)

On substracting (i) and (ii),

2y=6

y=3

putting y in (i),

x+4(3)=27

x=15

∴x=Rs.15 and y=Rs. 3

∴ Fixed charge =Rs. 15

∴ Charge for each extra day =Rs. 3