a, b, c numerele
a+b+c=?
2a=5b=4c=k
a=k/2
b=k/5
c=k/4
cel mai mic este b=k/5 (pentru ca il impartim pe k la cel mai mare nr dintre 2, 5 si 4)
b=k/5=144,(3)
k=5·144,(3)=5·(144+1/3)=720+5/3=720+1 2/3=721,(6)
a+b+c=k/2+k/5+k/4=10k/20+4k/20+5k/20=19k/20
a+b+c=19/20·(7216-721)/9=19/20·6495/9=19/4·1299/9=19/4·433/3=
=8227/12=685,58(3)