Răspuns:
Explicație pas cu pas:
Mihai + David = 55
Mihai + Radu = 77
David + Radu = 90
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Mihai + David + Radu = ( 55 + 77 + 90 ) : 2 = 222 : 2 = 111 cartonase
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Cate cartonase are Mihai?
111 - 90 = 21 cartonase are Mihai
Cate cartonase are David?
55 - 21 = 34 cartonase are David
Cate cartonase are Radu?
90 - 34 = 56 cartonase are Radu