[求助]GWD数学 求教高手！

以下是data sufficiency题目 (选项略去)

If p, s, and t are positive prime numbers, what is the value of p3s3t3? (3是3次方，我也不知道该怎么打啦~)

(1) p3st = 728

(2) t = 13

正确答案A 我选的E

A department manager distributed a number of pens, pencils, and pads among the staff in the department, with each staff member receiving x pens, y pencils, and z pads. How many staff members were in the department?

(1) The numbers of pens, pencils, and pads that each staff member received were in the ratio 2:3:4, respectively.

(2) The manager distributed a total of 18 pens, 27 pencils, and 36 pads.

正确答案C 我选的E

Last year in a group of 30 businesses, 21 reported a net profit and 15 had investments in foreign markets. How many of the businesses did not report a net profit nor invest in foreign markets last year?

(1)Last year 12 of the 30 businesses reported a net profit and had investments in foreign markets.

(2)Last year 24 of the 30 businesses reported a net profit or invested in foreign markets, or both.

正确答案D 我选的A

（对于这种and 和or，求比例的题我特别不在行，请各位高手支招！）

Machine M processes a certain chemical product at a constant rate. Does machine M process the product at a rate that is greater than 25 grams per second? (1 kilogram = 1,000 grams)

(1)Machine M processes the product at a rate that is greater than 92 kilograms per hour.

(2)Machine M processes the product at a rate that is less than 95 kilograms per hour.

正确答案A 我选的D

（既然1可以，2为什么不可以呢？）