Answer:
9 people should get on stop 1.
Step-by-step explanation:
If i understood it correctly .
13 people on bus initially.
at first stop - 4 people get off . So 9 people should be on bus.
But few get in bus ( that is what is asked in the question - but it is not super clear to me)
after 2nd stop - there are 12 people on bus.
at 2nd stop 6 people got off.. so there were total of 18 on the bus
So if there were 9 people on bus stop by stop 1 .. so 9 people should have got in bus at stop 1 to make it equal to 18.
Only doubt i have is : if the question is asking how many got on the 2nd stop. also i was not clear what does this line means - At the first stop, four people get off and to get on.
