Number of pages =10× time + Unread pages Number of pages =50 time =t unread pages =N 50=10×t+N Make N the subject N=−10t+50 You can verify the relation. Assuming the student reads for 5 hours. Number of unread pages (N)=−10×5+50 Number of unread pages (N)=−50+50 Number of unread pages (N)=0 This means a student will complete the story book in 5 hours time. Assuming the student reads for 4 hours. Number of unread pages (N)=−10×4+50 Number of unread pages (N)=−40+50 Number of unread pages (N)=10 This means after 4 hours, there will be 10 unread pages.