prima zi=64%din x=...=16x/25
a doua zi=50% din(x-16x/25)=1/2 ·(25x/25 - 16x/25)=1/2 · 9x/25=9x/50.
a treia zi=45.
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x=16x/25+9x/50+45=32x/50+9x/50+45=41x/50+45=41x+2250/50⇒50x=41x+2250⇒9x=2250⇒x=250.