55X-30=50X- 10

55X-50X=30- 10

5X=20

X=4

Cars =4 cars

Person =50*4- 10= 190.

Set two places x kilometers.

850-X=3.5( 105+76)

850-X=633.5

X=2 16.5

The distance between the two places is 2 16.5km.