DS2 求解

kuoyutzu

155.  15795-!-item-!-187;#058&010817

If 500 is the multiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y, which multiple of 100 is closest to x + y ?

 

(1) x < 500

 

(2) y < 400

ans(E)

166.  16673-!-item-!-187;#058&011115

If the prime numbers p and t are the only prime factors of the integer m, is m a multiple of p²t ?

 

(1) m has more than 9 positive factors.

 

(2) m is a multiple of p³.

ANS(B)

条件一错在哪??

179.  17563-!-item-!-187;#058&011544

Working independently at their respective constant rates, pumps X and Y took 48 minutes to fill an empty tank with water.  What fraction of the water in the full tank came from pump X ?

 

(1) Working alone at its constant rate, pump X would have taken 80 minutes to fill the tank with water.

 

(2) Working alone at its constant rate, pump Y would have taken 120 minutes to fill the tank with water.

ANS(D)

183.  17831-!-item-!-187;#058&011633

If m is a positive odd integer between 2 and 30, then m is divisible by how many different positive prime numbers?

 

(1) m is not divisible by 3.

 

(2) m is not divisible by 5.

ANS(A)

(2) m is not divisible by 5. 为何不行??