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jcan-gmatter
- Junior | Next Rank: 30 Posts
- Posts: 17
- Joined: Thu Jul 05, 2007 9:08 am
- Location: Kingston, Jamaica
Hello all,
Got the following question wrong on the practice powerprep test. After looking some more at the question, I worked out the following. Is it correct?
Question
In the graduating class of a certain college, 48% of the students are male and 52% are female. In this class 40% of the male and 20% of the female students are 25 years old or older. If one student in the graduating class is randomly selected, approximately what is the probability that he or she will be less than 25 years old?
A. 0.90
B. 0.70
C. 0.45
D. 0.30
E. 0.25
Working
P (M & < 25)
=> P(M) * P( < 25)
=> 0.48 * 0.60
=> 0.208
P (F & < 25)
=> P(F) * P(<25)
=> 0.52 * 0.80
=> 0.416
Therefore, P(<25) = 0.208 + 0.416 = 0.704.
Hence, answer is B.
Is the above working correct?
Got the following question wrong on the practice powerprep test. After looking some more at the question, I worked out the following. Is it correct?
Question
In the graduating class of a certain college, 48% of the students are male and 52% are female. In this class 40% of the male and 20% of the female students are 25 years old or older. If one student in the graduating class is randomly selected, approximately what is the probability that he or she will be less than 25 years old?
A. 0.90
B. 0.70
C. 0.45
D. 0.30
E. 0.25
Working
P (M & < 25)
=> P(M) * P( < 25)
=> 0.48 * 0.60
=> 0.208
P (F & < 25)
=> P(F) * P(<25)
=> 0.52 * 0.80
=> 0.416
Therefore, P(<25) = 0.208 + 0.416 = 0.704.
Hence, answer is B.
Is the above working correct?
