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On Saturday morning, Malachi will begin a camping vacation a
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07 Sep 2020, 04:44
07 Sep 2020, 04:44
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Question Stats:
75% (01:16) correct
25% (01:22) wrong based on 40 sessions
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On Saturday morning, Malachi will begin a camping vacation and he will return home at the end of the first day on which it rains. If on the first three days of the vacation the probability of rain on each day is 0.2, what is the probability that Malachi will return home at the end of the day on the following Monday?
A. 0.008
B. 0.128
C. 0.488
D. 0.512
E. 0.640
A. 0.008
B. 0.128
C. 0.488
D. 0.512
E. 0.640
Re: On Saturday morning, Malachi will begin a camping vacation a
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07 Sep 2020, 04:44
07 Sep 2020, 04:44
Expert Reply
Post A Detailed Correct Solution For The Above Questions And Get A Kudos.
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!
For more theory and practice see our GRE - Math Book
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Re: On Saturday morning, Malachi will begin a camping vacation a
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07 Sep 2020, 06:01
07 Sep 2020, 06:01
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Carcass wrote:
On Saturday morning, Malachi will begin a camping vacation and he will return home at the end of the first day on which it rains. If on the first three days of the vacation the probability of rain on each day is 0.2, what is the probability that Malachi will return home at the end of the day on the following Monday?
A. 0.008
B. 0.128
C. 0.488
D. 0.512
E. 0.640
A. 0.008
B. 0.128
C. 0.488
D. 0.512
E. 0.640
NOTE: if P(rain on a certain day) = 0.2, then we know that P(NO rain on a certain day) = 1 - 0.2 = 0.8
For probability questions, I always ask, "What needs to happen for the desired event to occur?"
For this question P(come home Monday night) = P(no rain on Saturday AND no rain on Sunday AND rain on Monday)
At this point, we can apply what we know about AND probabilities. We get:
P(come home Monday night) = P(no rain on Saturday) X P(no rain on Sunday) X P(rain on Monday)
= (0.8) X (0.8) X (0.2)
= 0.128
Answer: B
