[求助]XDF-DS-41 解题思路。谢谢！

LES

What fractional part of the total surface area of cube C is red?

(1) Each of 3 faces of C is exactly 1/2 red.

(2) Each of 3 faces of C is entirely white.

请教大家这题的解题思路。谢谢！

WONDERLAND2004

The total number of faces of any CUBE is 6.

Condition 1 says each of 3 faces of the CUBE is 1/2 RED; condition 2 says that the remaining faces of the CUBE are entirely WHITE. From both condition 1 and condition 2 together, we can work out the what fractional part of the total surface area of the cube is RED, which is: (3*1/2)/6=1/4.

LES

谢谢wonderland2004! 偶搞懂了！

原来偶的阅读理解有问题，其实是“其中三个面的每一面的一半是红色的”而偶理解成了“任意三个面中的一个面......”。虽然加“任意”自己也觉得不妥，因为文中没有“any”，但是总是对文中的表述觉得怪怪的。看来要尽快熟悉此种表达。

再次谢谢你！

WONDERLAND2004

不用谢。

我们都在互相帮助而已。