The original total speed was 100, but it became 120 after acceleration.

Original meeting time x rule

100x= 120(x-0.25)

x= 1.5

Distance1.5 *100 =150km.

2

400/ 1.5=267

400/2=200

This is the boss's purchase price range.

267* 1.2=320

200* 1.2=240

That is, you can make a counter-offer of 80- 160 yuan.

3.

X kilometers between the two cities, the original speed y

X/ 1.2Y = 100/y+(X- 100)/ 1.3y

You can eliminate y by multiplying y, and you get

x/ 1.2 = 100+(x- 100)/ 1.3

1.3x = 156+ 1.2x- 120

x=360