问几道GWD数学

windyYe

Q15:
If p is the product of the integers from 1 to 30, inclusive, what is the greatest integer k for which 3k is a factor of p?

A.    10
B.    12
C.    14
D.    16
E.    18

这题很奇怪，为什么我算的没有一个是对的。。。我算的是13


Q11:
Mary persuaded n friends to donate $500 each to her election campaign, and then each of these n friends persuaded n more people to donate $500 each to Mary’s campaign.  If no one donated more than once and if there were no other donations, what was the value of n?
(1)      The first n people donated   of the total amount donated.
(2)      The total amount donated was $120,000.


Q28:
Three printing presses, R, S, and T, working together at their respective constant rates, can do a certain printing job in 4 hours.  S and T, working together at their respective constant rates, can do the same job in 5 hours.  How many hours would it take R, working alone at its constant rate, to do the same job?

A.     8
B.    10
C.    12
D.    15
E.    20


Q37:
Of the 500 business people surveyed, 78 percent said that they use their laptop computers at home, 65 percent said that they use them in hotels, and 52 percent said that they use them both at home and in hotels.  How many of the business people surveyed said that they do not use their laptop computers either at home or in hotels?

A.    45
B.    55
C.    65
D.    95
E.    130


Q35:
Guy’s net income equals his gross income minus his deductions.  By what percent did Guy’s net income change on January 1, 1989, when both his gross income and his deductions increased?
(1)      Guy’s gross income increased by 4 percent on January 1, 1989.
(2)      Guy’s deductions increased by 15 percent on January 1, 1989.

谢谢大家~！