Huaying math problems

1。 Let b's speed be x kilometers per hour.

1*4+2(x+4)=32

The solution is x= 10.

So the speed of B is 10 km/h.

2. Set the time from pursuit to red machine firing as t minutes.

(22- 15)t=50- 1

The solution is t=7.

Plus 0.5 minutes from the fire to the crash

* * * 7.5 minutes.

3. Let the uphill speed be X km/h and the downhill speed be 2x km/h..

2x+2=(4/3)*2x

The solution is x=3.

Then 2x=6, and the length of mountain road 2x+2 = 8km.

4. If the speed of B is X km/h, then the speed of A is1.2xkm/h..

1.2x- 10 = 2/3 * x+ 10

X=37.5, then 1.2x=45.

The distance between AB is (1.2x- 10) * 2 = 70km.