艾易艾斯(aeas)数学推理讲解-2

Train A leaves Brisbane for Adelaide and travels at a constant speed. At the same time train B leave Adelaide for Brisbane and also travels at a constant speed.

Town X is between Brisbane and Adelaide. Brisbane, town X and Adelaide lie on a straight line. Which train has greater speed?

Which of following statements are sufficient to answer the question.

1. Train B arrives at town X before train A.
2. Town X is farther to Brisbane than Adelaide

a.Statement I alone is sufficient to answer the problem

b.Statement II alone is sufficient to answer the problem

c.Statements I and II both are needed

d.Statements I and II both are not sufficient

火车A匀速从Brisbane 驶向 Adelaide, 与此同时，火车B从Adelaide匀速驶向Brisbane.

小镇X在Brisbane 和 Adelaide之间且 小镇X 与Adelaide和Brisbane处于同一直线上。

附加以下哪个条件之后可以求出哪辆火车速度更快？

1. 火车B比火车A先到达小镇X
2. 小镇X离Brisbane比离Adelaide远

A 条件一

B 条件二

C 条件一和条件二

D 条件一和条件二都不充分

Explanation：

Step 1

To conclude which train has lesser speed. We need two information i.e which train is relatively faster and position of town X.

Step 2

So, Statements I and II both are not sufficient to understand the problem clearly.

Step 3

Hence, d is the correct option.