这几道题百思不得其解,希望高人可以解答一下^^
problem solving
1.if n is a positive interger and n^2 is divisible by 72, then the largest positive integer that must divide n is
a.6 b.12 c.24 d.36 e.48
2.a square countertop has a square tile inlay in the center, leaving an untiled strip of uniform width around the tile. if the ratio of the tiled area is 25 to 39, which of the following could be the width, in inches, of the strip?
(1).1 (2).3 (3).4
a.(1)only b.(2)only c.(1) and (2) only d. (1) and (3) only e. (1), (2), (3)
data sufficient
1. a home owner must pick between paint A, which costs $6.00 per liter, and paint B, which costs $4.50 per liter. Paint B takes one-third longer to apply than paint A. If the home owner must pay the cost of labor at the rate of $36 per hour, which of the two paints will be cheaper to apply?
(1) the ratio of the area covered by one liter of paint A to the area covered by paint B is 4:3
(2) paint A will require 40 liters of paint and 100 hours of labor
2. in a certain law firm there are five senior partners and all senior partners receive bonuses greater than those of the junior partner. Does senior partner Johnson receive the largest bonus of the lawyers at the firm?
(1) Johnson receives a bonus greater than twice the average bonus for all the senior partners.
(2) all partners receive some bonus, and Mr. Johnson receives five times the average given to all the partners. | 
