Answer 16., 17., and 18., text me after you

I'm not quite sure how I'd attach a picture of my working so I'll explain the method.

16) I multiplied both 3.5 and 40 by ten so that I could divide them to find the number of servings. 35 divided by 400 is 11 remainder 15. If you then divide the remainder by 10 you get 11 servings and 1.5 ounces left over.

17) if you add up 26, 17, and 37 inches you get 80 inches, or just over 6 feet. Hence, he should buy an 8 foot length rod in order to have as little waste as possible.

18) 12.25 pounds is 196 ounces. Hence, the shipping rate at $0.26/ounce would end up being $50.96. From this we can see that the flat-rate box at $25 is less expensive.