Ex 2.3, 5

Transcript

Ex 2.3, 5 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. Given that Number of pages in the book = 500 Pages read each day = 20 So, we can we can write Page left after 1 day = Number of pages – Pages read = 500 – 20 = 480 Page left after 2 days = Number of pages – Pages read × 2 = 500 – 20 × 2 = 500 – 40 = 460 Page left after 3 days = Number of pages – Pages read × 3 = 500 – 20 × 3 = 500 – 60 = 440 So, we can write that after Number of days = n Page left after n days = Number of pages – Pages read × 3 = 500 – 20 × n = 500 – 20n Now, we need to find number of pages will be left after 15 days Putting n = 15 in our formula Page left after 15 days = 500 – 20 × 15 = 500 – 300 = 200