Vrijeme: 08:50

VJEROJATNO sam gledao Suits već 5 puta | I’ve PROBABLY watched Suits five times already #4

Nakon što je Mike izašao iz zatvora (bio je zatvoren zbog bavljenja pravom bez diplome), nije nikako mogao pronaći nocvi posao pa je ponovno morao tražiti alternativne metode za zaradu. Jedna od tih metoda bila je skupljanje školjki od kojih izrađuje broševe ili narukvice. Dok ih izrađuje, nikad ne zna što će na kraju izraditi, ali s vjerojatnošću \frac{2}{3} mu ispadne broš, a s vjerojatnošću \frac{1}{3} narukvica. Svoje proizvode prodaje po New Yorku - broševe po 5 dolara, a narukvice po 7 dolara. Cilj mu je zaraditi dovoljno za novi bicikl koji stoji 500 dolara. Koliko školjaka mora sakupiti da bi s vjerojatnošću od 0.90 zaradio dovoljno za novi bicikl?
After Mike got out of prison (where he was locked up for practicing law without a degree), he struggled to find a regular job and had to look for alternative methods to earn money again. One of those methods was collecting shells from which he makes brooches or bracelets. While making them, he never knows what he will end up with, but he has a probability of \frac{2}{3} of making a brooch and a probability of \frac{1}{3} of making a bracelet. He sells his products in New York—brooches for $5 and bracelets for $7. His goal is to earn enough for a new bike that costs $500. How many shells does he need to collect to have a 0.90 probability of earning enough for the new bike?