Question

Ana si Bogdan au impreuna 7 mere,iar Ana si Calin au impreuna 8 mere. Cate mere are Ana daca in total copii au 12 mere?

Answer 1

a+b=7 mere (Ana+Bogdan)
a+c=8 mere (Ana+Calin)
a+b+c=12 mere (Ana+Bogdan+Calin)
7+c=12
c=12-7
c=5 mere are Calin
8+b=12
b=12-8
b=4 mere are Bogdan
a+4+5=12
a+9=12
a=12-9
a=3 mere are Ana
V: 3+4+5=12 mere (A+B+C)