the answer is C because if you divide 84 by 7 you get 12 so you then multiply 6 by 12 and get 72. the answer could not be negative 72 because that would then make the equation positive.
Well if you add 14 and 21 you get 35. with 35 you can have 7 groups of 5 but if they have to be equal with the number of boys and girls in each group it would still be 7. two boys in each group with three girls in each group.
