Question 1176452
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What do you not understand about this problem?  Solving it requires only basic concepts about probability....<br>
a. a geology project AND then a chemistry project are the first two to be judged<br>
There are 15 projects in all; 5 of them are geology, so the probability of judging a geology project first is 5/15.<br>
After that, there are 14 projects left, of which 3 are chemistry; the probability of judging a chemistry project second is 3/14.<br>
Since you want both things to happen (the events are connected by "AND"), you multiply the probabilities.<br>
P(geology first AND chemistry second) = (5/15)(3/14) = (1/3)(3/14) = 1/14<br>
Solve the others the same way:<br>
P(biology first AND physics second) = (?)(?) = ...<br>
P(physics first and physics second) = (?)(?) = ...<br>