What is 25/60 in simplest fron

Pls! does anybody know a shortcut for answering these types of questions in the future?

On a piece of paper, graph y< x+1. then determine which answer matches the graph you drew.

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )