Question

Ana si Bogdan au impreuna 7 mere,iar Ana si Calin au impreuna 8 mere.Determinati cate mere are Ana,stiind ca,impreuna,cei trei copii au 12 mere.

Answer 1

a+b=7
a+c=8
a+b+c=12
a+a+b+c=15 =>a+12=15 =>a=3
b=7-a=7-3=4
c=8-a=8-3=5