61ft = how much volume

What number line represents the solution set for the inequality -1/2 greater than or equal to 4

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! )

What is the answer to the question 5x+2x