Complete Question
Professor Jin wants to travel from place A to place B without a map. There are four ways lead away from place A. If road I is selected, the probability of arriving place B is 1/8; if road II is selected, the probability of arriving place B is 1/6; if road III is selected, the probability of arriving place B is 1/4; and if road IV is selected,the probability of arriving place B is 9/10.
(a) What is the probability that professor will arrive at place B?
(b) If Professor Jin arrives at place B, what is the probability that she chooses road IV?
Answer:
a
[tex]P(B) = 0.36[/tex]
b
[tex]P(4 /B) = 0.62[/tex]
Step-by-step explanation:
From the question we are told that
The number of ways from A to B is n = 4
The probability if road 1 is selected is [tex]P(1) = \frac{1}{8}[/tex]
The probability if road 2 is selected is [tex]P(2) = \frac{1}{6}[/tex]
The probability if road 3 is selected is [tex]P(3) = \frac{1}{4}[/tex]
he probability if road 4 is selected is [tex]P(4) = \frac{9}{10}[/tex]
The probability that professor will arrive at place B is mathematically represented as
[tex]P(B) = \frac{1}{n} * P(1) + \frac{1}{n} * P(2) + \frac{1}{n} * P(3)+ \frac{1}{n} * P(4)[/tex]
[tex]P(B) = \frac{1}{4} * \frac{1}{8} + \frac{1}{4} * \frac{1}{6} + \frac{1}{4} * \frac{1}{4} + \frac{1}{4} * \frac{9}{10}[/tex]
[tex]P(B) = 0.36[/tex]
If Professor Jin arrives at place B, what is the probability that she chooses road IV is mathematically represented as
[tex]P(4 /B) = \frac{ \frac{1}{n} * P(4)}{P(B)}[/tex]
=> [tex]P(4 /B) = \frac{ \frac{1}{4} * \frac{9}{10} }{0.36}[/tex]
=> [tex]P(4 /B) = 0.62[/tex]
