 <translate> Let the boys are X, then girls are 7X, total = X+7X = 8X
So it should be multiple of 8, 30 is not a multiple of 8.
The final answer: (C). <yor> Jẹ ki awọn ọmọkunrin jẹ X, lẹhinna awọn ọmọbirin jẹ 7X, lapapọ = X + 7X = 8X Nítorí náà, ó yẹ kó jẹ́ ìlọ́po 8, 30 kì í ṣe ìlọ́po 8. Ìdáhùn tó péye: (C). 