This is the concept of algebra,
The fraction of children was: 3/8
fraction of adults was 1-3/8=5/8
fraction of men 3/4*5/8=15/32
fraction of women=5/8-15/32=5/32
Given that there was 140 more children than men, the fraction representing this will be:
(3/8-5/32)
=7/32
thus the total number of people will be:
1/(7/32)*140
=32/7*140
=640
the total number of people was 640
