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A class consists of students born in a certain year, where at least tw
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Updated on: 03 May 2022, 11:29
Updated on: 03 May 2022, 11:29
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A class consists of students born in a certain year, where at least two people were born in each month of the year.
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
The probability that two randomly-selected students were born in the same month |
The probability that two randomly-selected students were born in different months |
A) Quantity A is greater.
B) Quantity B is greater.
C) The two quantities are equal.
D) The relationship cannot be determined from the information given.
Part of the project: Skill Builder Project for a Q170
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
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Re: A class consists of students born in a certain year, where at least tw
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03 May 2022, 11:21
03 May 2022, 11:21
4
Carcass wrote:
A class consists of students born in a certain year, where at least two people were born in each month of the year.
Quantity A |
Quantity B |
The probability that two randomly-selected students were born in the same month |
The probability that two randomly-selected students were born in different months |
The correct answer is D.
Consider two cases:
Case i: The class consists of:
2 students born in January
2 students born in February,
2 students born in March
2 students born in April
.
.
2 students born in December
Now let's choose the first student at random.
At this point there are 23 students remaining.
1 of those 23 students was born in the same month as the first selected student, which means P(born in the same month) = 1/23
22 of those 23 students were born in a month different from the first selected student, which means P(born in different months) = 22/23
In this case, Quantity B is greater.
Case ii: The class consists of:
2 students born in January
2 students born in February,
2 students born in March
2 students born in April
.
.
2 students born in November
1,000,000,000,000 students born in December
In this case, it's pretty clear that the two selected students will probably be born in December.
Consequently, it's extremely unlikely that the two selected students will both be born in different months.
So, in this case, Quantity A is greater.
Answer: D
General Discussion
Re: A class consists of students born in a certain year, where at least tw
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03 May 2022, 09:21
03 May 2022, 09:21
How to solve this question?
