JAMB Mathematics 2021 Paper

Concept:This is a three-set problem; subtract the shared regions carefully and then add all disjoint parts.Explanation:Let $M$ represent maize, $Y$ represent yam, and $P$ represent plantain.Women who sell all three items: $n(M \cap Y \cap P) = 3$.Those selling plantain and maize only: $5 - 3 = 2$.Those selling yam and maize only: $4 - 3 = 1$.Those selling yam and plantain only: $2$ as given.Now find those selling only one item:Maize only: $12 - (1 + 2 + 3) = 6$.Yam only: $10 - (1 + 2 + 3) = 4$.Plantain only: $14 - (2 + 2 + 3) = 7$.Add all the distinct groups:$6 + 4 + 7 + 1 + 2 + 2 + 3 = 25$.Answer:The number of women in the group is $25$, so the correct option is A.