题目

Worst Game Ever？        E.T. the Extra-Terrestrial is a video game that came out for the Atari 2600 game system in 1982. It was based on a very popular film of the same name. Star programmer Howard Warshaw created it with consultation from the film director Steven Spielberg.        It was July 27th, 1982. Howard Warshaw was hot off the success of his most recent game, Raiders of the Lost Ark. He received a call from Atari C.E.O, Ray Kassar. Atari had bought the rights to make a video game version of Spilberg’s Movie, E.T., which had just been released（发行） in Jun（2012•广州二模）如图，A，B两点之间有6条网线连接，每条网线能通过的最大信息量分别为1，1，2，2，3，4．从中任取三条网线且使每条网线通过最大信息量，设这三条网线通过的最大信息量之和为ξ．（1）当ξ≥6时，则保证线路信息畅通，求线路信息畅通的概率；（2）求ξ的分布列和数学期望．