Please tell of all tick the correct ka answer

Dear Student, 

Ans 7. Option D is correct. Since second / metre can not be its unit.
Ans 8. Option C is correct.  Multiply 20 with 18/5 to convert in km/hr that will be 72km/hr.
Ans 9.  Average speed= Total distance divided by total time.
                   Average speed = 150 /3 = 50km/h
          Hence, correct option is option C.
Ans 10. The correct option is option C. 
                Distance = average speed × time = 60×5.5= 330km

Regards