Cinci gaini fac 15 oua in 4 zile.Cate oua fac doua gaini in opt zile??

Răspuns :

5 gaini...15 oua...4 zile
2 gaini...x oua ...4 zile
x=2×15/5=2×3=6 oua in 4 zile => 12 oua in 8 zile