4X+(200-X)/2* 1= 120

8X+200-X=240

7X=40

X=5.7

No answer

2, 26130% = 20 (person)

3,35 (1-65%) * 2 = 200 (km)

4.1-65% = 35% 35 ÷ 35% =100 (km)

5. 180*80%= 144 (yuan) 180- 1447=36 (yuan)