GMAT數(shù)學精華題型實例解析(2)

PREP

7. 905-!-item-!-187;#058&000575

For every positive even integer n, the function h(n) is defined to be the product of all the even integers from 2 to n, inclusive. If p is the smallest prime factor of h(100) + 1, then p is 用余數(shù)來解決

(A) between 2 and 10

(B) between 10 and 20

(C) between 20 and 30

(D) between 30 and 40

(E) greater than 40

選E

34. 2927-!-item-!-187;#058&003024

During an experiment, some water was removed from each of 6 water tanks. If the standard deviation of the volumes of water in the tanks at the beginning of the experiment was 10 gallons, what was the standard deviation of the volumes of water in the tanks at the end of the experiment?

(1) For each tank, 30 percent of the volume of water that was in the tank at the beginning of the experiment was removed during the experiment.

(2) The average (arithmetic mean) volume of water in the tanks at the end of the experiment was 63 gallons.

36. 4841-!-item-!-187;#058&004235

In a certain deck of cards, each card has a positive integer written on it. In a multiplication game, a child draws(抽) a card and multiplies the integer on the card by the next larger integer(下一個數(shù)). If each possible product is between 15 and 200, then the least and greatest integers on the cards could be

(A) 3 and 15

(B) 3 and 20

(C) 4 and 13

(D) 4 and 14

(E) 5 and 14

【答案】C

48. 6225-!-item-!-187;#058&004914

A certain city with a population of 132,000 is to be divided into 11 voting districts, and no district is to have a population that is more than 10 percent greater than the population of any other district. What is the minimum possible population that the least populated district could have?

最大比其他城市大不超過10%，那就設除了最小的以外都比它大10%

(A) 10,700

(B) 10,800

(C) 10,900

(D) 11,000

(E) 11,100

【答案】D