Cu ouale dintr-un cos pot umple 8 cutii a cate 6 oua si imi mai lipsesc cateva oua pentru a umple a 9-a cutie.Cu ouale din 4 cosuri identice pot umple 33 de cutii a cate 6 oua si imi lipsesc cateva oua pentru a umple a 34-a cutie.Cate oua sunt intr-un cos?

8 cutii × 6 oua + (6 - x )oua → intr-un cos

8 cutii × 6 oua + ( 6 - x ) oua → al doilea cos

8 cutii × 6 oua + ( 6 - x ) oua → al treilea cos

8 cutii × 6 oua + ( 6 - x ) oua → al patrulea cos

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Total = 33 cutii × 6 oua + ( 6 - x)

4 × ( 8 cutii × 6 oua ) = 32 de cutii × 6 oua

33 - 32 = 1 cutie × 6 oua

+ ( 6 - x) ⇒

4 cosuri × 1 ou < 6 oua

4 cos uri × 2 oua = 1 cutie × 6 oua + 2 oua → varianta corecta

4 cosuri × 3 oua =32 cutii + 2 cutii > 33 cutii

→ deducem ca in fiecare cos sunt 8 cutii a cate 6 oua si inca 2 oua

8 cutii × 6 oua + 2 oua = 48 oua + 2 oua = 50 oua sunt intr-un cos

Raspuns: 50 oua sunt intr-un cos