4. solution: let the population of another village be x.

x+(2x-3)=834

x+2x-3=834

3x=834+3

3x=837

x=279

Larger villages: 934-279=555 (people)

5. solution: suppose it took B X to climb to the top of the mountain.

10(x+30)= 15x

10x+300= 15x

10x- 15x=-300

-5x=-300

x=60

A's time is: 60+30=90 minutes.

The height of the mountain is 60 times 15=900 meters.

6. solution: let the speed of electric locomotive be x km/h.

1/2x+ 1/2(5x+20)= 298

1/2x+5/2x+ 10=298

3x+ 10=298

3x=288

x=96

The speed of maglev train is 96 times 5+20=500.

7. Solution: The windless wind speed is X, the downwind wind speed is (x+24), and the upwind wind speed is (x-24).

2 hours and 50 minutes = 17/6 hours

17/6(x+24)=3(x-24)

17/6x+68=3x-72

17/6x-3x=-68-72

- 1/6x=- 140

x=840

Range: 3X(840-24)

=3X8 16

=2448 km

I typed it word for word, and 100% was correct, because I got 100 for this assignment. Hehe'