Trina has 72 collectors said she put 43 of these stamps into a stamp book how many states are left

What is the solution to the equation? k/6.4=8.7 2.3 5.568 15.1 55.68

I’m on question 7 it says a covered water tank is in the shape of a cylinder the tank has a 28 inch diameter and a height of 66 inches to the nearest square inch what is the surface area of the water tank

5, 6, 10 question: a. determine whether the side lengths form a triangle. (explain your reasoning) b. if it is a triangle, determine whether it is a right, acute, or obtuse triangle. (show your work)