Question

Bunicul are 26 gaste, curci si rate. Stiind ca gaste si curci sunt 20,iar curci si rate sunt 14,afla cate pasari de fiecare are bunicul.

Answer 1

a+b+c = 26
a+b = 20
b+c = 14
-------
a+b = 20
20+c = 26 => c = 26-20 = 6  (rate).
b+c = 14 => b+6 = 14 => b = 14 -6 = 8 (curci).
a+b = 20 => a+8 = 20 => a = 20-8 = 12 (gaste).

In notarea mea:
a - gaste
b - curci
c - rate