Răspuns:
aplicam teorema impartirii cu rest
D=I·C+R
27=n·c₁+21
36=n·c₂+30
48=n·c₃+42
27-21=n·c₁=>nc₁=6
36-30=n·c₂=>nc₂=6
48-42=n·c₃=>nc₃=6
cmmmc(27,36,48)=2⁴·3³=432
n+6=432=>n=432-6=>n=426
verificare:
426:27=15 rest 21
426:36=11 rest 30
426:48=8 rest 42