Anyone know the answer?

Which equation expression the relationship between the number of boxes b and the number of cans c and the proportion is 48

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! )

Sara made $253 for 11 hours of work. at the same rate how much would he make for 7 hours of work?