According to the meaning of the question, when the wind force in the typhoon center is 12, the wind force 200 kilometers away from the center is 4.

If point A is AD⊥BC in D, then point D is the closest point of typhoon center to city A.

It is known that ABC = 30, AB=240 km,

Available: AD = 120km? & lt？ 200 kilometers,

Therefore, City A will be affected by the typhoon.

2、

Suppose that when city A begins to be affected by the typhoon, the center of the typhoon is point E; When city A is affected by typhoon, the typhoon center is point F; Yes: AE=AF=200 kilometers.

Available: DE = DF = 160km, EF = 320km.

Therefore, the duration of typhoon affecting city A is: 320/20? =? 16? hour

3、

Because, when the typhoon center reaches the nearest D point to A city, A city is the most affected by the wind.

So, it can be calculated: 12? -? 120/25? =? 7.2? ;

Taking the whole number, we can get: What is the maximum wind force affected by typhoon in City A? 7? Level.