Răspuns :
- a = egrete
- b = ibisi
- c = starci
a+b+c=854
a+b=622
b+c=742
622+c=854
c= 854-622
c=232
b+232=742
b=742-232
b= 510
a+510=622
a=622-510
a=112
sau :
854-622=232 ( stârci )
742-232=510 ( ibisi )
622-510=112 ( egrete )
egrete+ibisi+starci=854
egrete+ibisi=622
ibisi+starci=742
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1.Cati starci sunt?
854-622=232(starci)
2.Cati ibisi sunt?
742-232=510(ibisi)
3.Cate egrete sunt?
622-510=112(egrete)
Raspuns : 232 starci, 510 ibisi, 112 egrete.