Răspuns :

Notam:

A= Ana

C= Cora

S= Sandu

A+C+S= 637

A=2C

S= 4C

2C+C+4C= 637 ⇔7C= 637 ⇔ C= 637÷7 ⇔ C= 91

A=2C ⇔A=2*91 ⇔ A= 182

S= 4C ⇔ S= 4*91 ⇔ S= 364

Ana are 182 bile, Cora are 91 bile, iar Sandu are 364 bile.