GWD3这两个题反复做了很多遍，还是不会``

ningxiaoye

How many seconds will it take for a car that is traveling at a constant rate of 45 miles per hour to travel a distance of 22 yards?    (1 mile = 1,160 yards)

 

A.     8

B.     9

C.     10

D.     11

E.      12 Answer: C  （22*3600）/（45*1160）=1。5？

If M is the least common multiple of 90, 196, and 300, which of the following is NOT a factor of M?最小公倍数怎么求啊？

 

A.     600

B.     700

C.     900

D.     2,100

E.      4,900

Answer: A

fantacy1220

第一题不会

第二题:

90=2*3*3*5

196=2*7*7

300=2*3*5*5

The least common multiple= (2*2)*(3*3)*(5*5)*(7*7)

600=(2*2*2)*3*5*5à3个2连乘,故此答案错

laipiyu

第一题题目应该有错：1 mile = 1,760 yards；a distance of 220 yards；如此改过以后答案是C

第二题如楼上所说。分解质因子可得。

ningxiaoye

非常感谢!!!呵呵

treo650

300=2*2*3*5*5

sourceme

3楼确实是个牛人。连1mile=1760 yards都这么清楚。