Solve d/3+5/6=4.write your answer as a mixed number

Can you me find the missing length. i attached an image.

If you have 12 feet of string and you cut it into equal length of 5 inches each how much string will be left

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! )