The population of a town in three consecutive years are 5000, 7000 and 8400 respectively. The population of the town in the fourth consecutive year according to geometrical increase method is________________?

1) involves successive trials
2) takes economic aspects into account
3) is time consuming
The correct answer is?
A. only (1)
B. (1)and(2)
C. (1) and (3)
D. all are correct

1) slower filtration rate
2) higher filtration rate
3) lesser efficiency in removal of bacteria
4) higher efficiency in removal of bacteria
The correct answer is?
A. (1) and (2)
B. (2) and (3)
C. (1) and (4)
D. (2) and (4)

A. house sewer
B. lateral sewer
C. intercepting sewer
D. submain sewer