Depends how you read it. "7 men have 7 wives" - is that (a.) 7 wives each, or (b.) 7 wives between them, in which case it would be reasonable to assume that was one each? "each man and each wife have 7 children" - is that (c.) 7 children per parent, i.e 14 children per couple if (b.) above were the case; or (d.) 7 children between them, which would probably only apply for case (b.)
So, if you assume reading it as (a.) and (c.), it would be 7 men plus 49 wives plus (49+7)*7 kids = 448 people. If you assume (b.) and (c.) it would be 7 men plus 7 wives plus 14*7 kids = 112 people. If you assume (b.) and (d.) it would be 7 men plus 7 wives plus 7*7 kids = 63 people.
Any other interpretations that get to a different number?
