20 12 On September 7th, an earthquake occurred at the junction of yiliang county, Zhaotong City, Yunnan Province and Bijie Prefecture, Guizhou Province, which caused landslides.

(1) The damaged road is 1km long, so the actual driving distance of the two engineering teams is176-1=175km.

Let the speed of team B be X, then the speed of team A is 1.5x+5, according to the meaning of the question.

(1.5x+5) * (10-8)+x * (10.5-8) =175, that is, 3x+10+5.5x =/kloc-

So the speed of Team A is 1.5x+5=50km/h, and the speed of Team B is 30km/h..

(2) Team A's efficiency in completing the quantities is1/24/0.5 =112, that is,112 for completing the quantities every hour.

If the two teams finish the road dredging task in the afternoon 16, the efficiency of team b is (1-kloc-0/12 * (16-10))/(16-) Therefore, if only Team B clears the expressway, it needs1(111) =11hour.