2, 5 seconds

3.x = 5y 10y+x+36 = 10x+y 15y+36 = 50y+YY = 1x = 5。 Ten digits are 1 and one digit is 5.

4. X+2x+14x = 25,500x = 1500. Model I produces1500 units, Model II produces 3,000 units, and Model II produces 2 1000 units.

(50-1)/(22-15)+0.5 = t t = 7.5 It took an enemy plane seven and a half minutes to escape and be annihilated.

6. X+20% X = 6000Y-20% Y = 6000X = 5000Y = 7500 Shareholders gain from A shares 1000 yuan, and lose from B shares 1500 yuan, resulting in a total loss of 500 yuan.