Critical Reasoning

In a monogamous culture, 100% of the adults are married. The average number of children per family is five and over-population is a threat. Programs to encourage birth-control have been ineffective. It has been suggested that this failure is due to these programs ignoring a tradition that values male children very highly, so that every parent wants to have at least one son. It is proposed that couples be encouraged to use birth-control measures after the birth of their first son.

If this proposal is widely accepted in the culture, we may expect that:

(A) the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females.
(B) the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present.
(C) the rate of population growth will remain the same, and future generations will contain a disproportionately high number of females.
(D) there will be no significant effect either on population growth or on gender balance.
(E) the population will decline precipitously, because approximately half of all families will have only a single child

mehaksal wrote:In a monogamous culture, 100% of the adults are married. The average number of children per family is five and over-population is a threat. Programs to encourage birth-control have been ineffective. It has been suggested that this failure is due to these programs ignoring a tradition that values male children very highly, so that every parent wants to have at least one son. It is proposed that couples be encouraged to use birth-control measures after the birth of their first son.

If this proposal is widely accepted in the culture, we may expect that:

(A) the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females.
(B) the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present.
(C) the rate of population growth will remain the same, and future generations will contain a disproportionately high number of females.
(D) there will be no significant effect either on population growth or on gender balance.
(E) the population will decline precipitously, because approximately half of all families will have only a single child

Looks like a probability question

In my opinion we can infer only E.

Proposal: Use birth-control measures after the birth of their first son.

The first child will be either male or female. So, in 50% of the cases, first child will be a male, and if the proposal is widely accepted, the couple will not have no more kids after that. This would result in steep declining of population.

Please post the OA and OE.

A--I don't think we can conclude the future generations will contain a disproportionately high number of females
B--We don't know what the current gender balance is, so I don't think we can determine the future gender balance
C--Population growth will definitely slow down
D--There will definitely be an effect on population growth, though not necessarily on gender balance.

This leaves us with E. If the probability of having a son or daughter is 50/50, and families use birth control after their first son, then half of all families will stop having children after their first child. Given that the current average number of children per family is 5, this will cause that average to decrease severely, which should decrease the population.

All in all, though, I don't think this is a GMAT-accurate question.

Bill...doesn't B seem ok??

I would like to go with D.

E should be wrong as how can we be sure abt approximately half of all families will have only a single child

In probability we have range from 0 to 1...there is not enough data provided to conclude result at around 0.5.

Hey can anybody post the OA and OE for this, along with the explanation?

IMO D

Since it is argued that the current birth control program has failed(avg number of children did not decrease) because people want a male heir. Somehow i infer that the probability of a child being girl is high and hence if a birth control program is initiated after the first male heir the average number of children might no decrease significantly. Hence D

If birth control policy is adopted, Family will stop as soon as it gives birth to male, otherwise keep on giving births. kids in all family will follow below format(Male-M,Female-F).

M
FM
FFM
FFFM
FFFFM

There is 50% chances of having male and female. Probability of 1/2. Consider, Society of 64 families. What would be result of birth control policy ?

Out of 64 families, 32 will have 32 boys, and 32 girls. Families with 32 boys will stop there.
Remaining 32 families will look for second kid. So,There 16 will be male and 16 female kids. 16 Families with second baby boy will stop there.
Remaining 16 families with 2 girls will look for 3rd kid. Out of 16 kids, 8 will be male and 8 female kids. 8 families will stop with 2 girls and 1 boy.
Remaining 8 families with 3 girls, will look for 4th kid... This way continues..

Concludingly,
32 Families will have 1 Male kid. =>(32M)
16 Families will have 1 Female, 1 Male kid. =>(16F, 16M)
8 Families will have 2 Female, 1 Male kid =>(16F, 8M)
4 Families will have 3 Female, 1 Male kid. =>(12F,4M)
2 Families will have 4 Female, 1 Male kid. =>(8F,2M)
1 Family will have 5 Females,1 Male kid. =>(5F,1M)
1 Family will have 6 Females. =>(6F)


Overall, 64 families will give birth to 63 males, 63 females. So, There will be gender balance after this policy. Answer B matches with this conclusion.

And obviously, We could only conclude, Population growth will be slow as there is birth control policy working.

Option E is also correct, but it uses extreme word 'precipitously'. I would chose B, rather than E. My Answer:B

mehaksal wrote:In a monogamous culture, 100% of the adults are married. The average number of children per family is five and over-population is a threat. Programs to encourage birth-control have been ineffective. It has been suggested that this failure is due to these programs ignoring a tradition that values male children very highly, so that every parent wants to have at least one son. It is proposed that couples be encouraged to use birth-control measures after the birth of their first son.

If this proposal is widely accepted in the culture, we may expect that:

(A) the rate of population increase will be slowed, and future generations will contain a disproportionately high number of females.
(B) the rate of population increase will be slowed, and the gender balance in future generations will remain as it is at present.
(C) the rate of population growth will remain the same, and future generations will contain a disproportionately high number of females.
(D) there will be no significant effect either on population growth or on gender balance.
(E) the population will decline precipitously, because approximately half of all families will have only a single child

IMO - A

Currently, there are equal number of females and males because everyone is married.

In the current scenario, the average number of females per family - m and the average number of females per family - m

when the latest policy is adopted, the families will be satisfied culturally (at least 1 son) but number of sons per family will go down from m to 1

and thus disproportionate number of females.

IMO B is the answer. The tradition was the reason why the programs failed. That means they were having daughters while waiting for a son and the number of daughters was definitely bigger than the number of sons. There were also couples they would go for the second son and had a few daughters before getting that second son. Choice B eliminates those couples that were going for more than one son.

+1 for B

PS: if you think think is confusing, then gmat test will be super confusing for you. Get used to the confusions.

IMO A

Since people will start using birth control after one son therefore population growth will decline. This rules out C and D.

Since most families will have a maximum of 1son whereas other families have two, three or more daughters.

Not enough information is provided to chose E. even if 50% of the population has one son, we don't know what percentage would have one, two, three and more daughters with at max one or no sons. Don't expect GMAT questions to expect that without this infomation we can find the solution. Therefore ruled out E

Between A and B, I ruled out B because all families will have at max one son whereas there is no limit to girls.even if 50% of the population will have max one son then the rest of 50% will have one or more than one daughters. Hence there will be a disproportionate number of females. This rules out B

Answer is A

mehaksal wrote:Bill...doesn't B seem ok??

B is the right answer.

If you assume 50% of families have a son first, the other families have a probability that 50% might first have a girl ( 1G and 1B ) or maybe 2G and 1B or 3G and 1B.

As we have 50% of families with first child as a son only, it is very likely that the gender balance will remain the same.

Hence, I choose B

Seems B is the right answer

https://gmatclub.com/blog/2012/07/gmat-q ... reasoning/


Bill ..pls shed some light on choice B

I am not getting a clear answer to this question.

I got D.

But if we look at E we can't estimate straight away estimate that half of all the families will have single child coz what if 75% of the families have two girls and then a boy.

In D too I am not convinced with the first part. But still will go for it

What is the OA???