The oasis outpost of Abu Ilan, in the heart of the Negev desert, has a population of 20 Bedouin tribesmen and 20 Farima tribesmen. El Kamin, a nearby oasis, has a population of 32 Bedouins and 8 Farima. A lost Israeli soldier, accidentally separated from his army unit, is wandering through the desert and arrives at the edge of one of the oases. The soldier has no idea which oasis he has found, but the first person he spots at a distance is a Bedouin. What is the probability that he wandered into Abu Ilahn? What is the probability that he is in El Kamin?
Bedouin Farima Total
Abu Ilan 20 20 40
El Kamin 32 8 40
Probability of Spotting a bedouin = Probability of selecting Abu Ilan x Probability of selecting a Bedouin in Abu Ilan +Probability of selecting El Kamin x Probability of selecting a Bedouin in El ...
The solution calculates conditional probability: Probability that the oasis is Abu Ilan given that the person spotted is a Bedouin & Probability that the oasis is El Kamin given that the person spotted is a Bedouin.