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If during a one-day period the Q train arrives at the
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25 Apr 2017, 16:48
25 Apr 2017, 16:48
Expert Reply
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Question Stats:
88% (00:58) correct
11% (01:27) wrong based on 17 sessions
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If during a one-day period the Q train arrives at the station 30% less frequently than the B train, and the B train arrives 10% less frequently than the F train, then the Q train’s frequency is what percent of the F train’s frequency?
A. 27
B. 40
C. 60
D. 63
E. 90
A. 27
B. 40
C. 60
D. 63
E. 90
Drill 4
Question: 4
Page: 321
Question: 4
Page: 321
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Joined: 01 Apr 2017
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WE:Analyst (Computer Software)
Re: If during a one-day period the Q train arrives at the
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26 Apr 2017, 11:44
26 Apr 2017, 11:44
Q train arrives at the station 30% less frequently than the B train => Q = .70B
B train arrives 10% less frequently than the F train => B = .90F
Now, to calculate Q train’s frequency to that of F train’s frequency in terms of percentage=> Q = .70B
Q = .70(.90F)
Q = .63F
Q = 63/100F
Q = 63%F
Therefore , Q train’s frequency would be 63% of the F train’s frequency.Option (D).
B train arrives 10% less frequently than the F train => B = .90F
Now, to calculate Q train’s frequency to that of F train’s frequency in terms of percentage=> Q = .70B
Q = .70(.90F)
Q = .63F
Q = 63/100F
Q = 63%F
Therefore , Q train’s frequency would be 63% of the F train’s frequency.Option (D).
Re: If during a one-day period the Q train arrives at the
[#permalink]
02 May 2017, 16:58
02 May 2017, 16:58
Expert Reply
Explanation
To solve this question Plug In. Since the question deals with percents, try 100. If the F train arrives 100 times per day, then the B will arrive 10% fewer times than 100:
\(B = (1- \frac{10}{100}) \times 100=90\) times,
and the Q will arrive 30% fewer times than 90: \(Q = (1 - 30/100) B = ( \frac{70}{30})90 = 63\) times.
Translating the question “the Q train’s frequency is what percentage of the F train’s” gives \(Q = \frac{x}{100} \times F\) or \(x = 63\).
Which means that the Q’s frequency is 63% of the F’s. The correct answer is choice (D).
Hence option D is correct!
To solve this question Plug In. Since the question deals with percents, try 100. If the F train arrives 100 times per day, then the B will arrive 10% fewer times than 100:
\(B = (1- \frac{10}{100}) \times 100=90\) times,
and the Q will arrive 30% fewer times than 90: \(Q = (1 - 30/100) B = ( \frac{70}{30})90 = 63\) times.
Translating the question “the Q train’s frequency is what percentage of the F train’s” gives \(Q = \frac{x}{100} \times F\) or \(x = 63\).
Which means that the Q’s frequency is 63% of the F’s. The correct answer is choice (D).
Hence option D is correct!
