Question

Determinati numarul abcd astfel incat ab/5 = cd/4 = ca/3 = db/15

Answer 1

12ab=15cd=20ca=4db


3ab=db =>b=0; 3a=d
4ab=5cd =>40a=50c+15a =>a=2c

presupunem a=1,
d=3: c=0-5, => nu e posibil
pp a=2 =>d=6:c=1
abcd=2016
a=3 =>c=1.5, nu e posibil
răspuns: abcd=2016