Sarita is reading a book of 500 pages. She reads 20 pages every day. How many pages will be left after
15 days? Express this as a linear pattern. [Page No. 24]

Here, total number of pages = 500

Number of pages read every day = 20

Pages left after $d$ days = 500 - 20d

After 15 days, number of pages = 500 - 20(15) = 500 - 300 = 200 pages left.