Sentence Correction

The first detailed study of magpie attacks in Australia indicates that by the time they had reached adulthood, 98 percent of men and 75 percent of women born in country have been attacked by the birds.
a) by the time they had reached adulthood, 98 percent of men and 75 percent of women born in country have been attacked by the birds.
b) by the time they reach adulthood, 98 percent of men and 75 percent of women, who were born in the country, had been attacked by birds.
c) by the time they reach adulthood, 98 percent of men and 75 percent of the women born in the country had been attacked by the birds.
d) 98 percent of the men and 75 percent of the women that were born in the country were attacked by the birds by the time they reach adulthood.
e) 98 percent of men and 75 percent of women who were born in the country, by the time they reached adulthood had been attacked by birds

OA is C, can anyone explain why B and E is wrong..

{B} 98% of Men & 75% of women, who were born .. --> this gives the meaning that 98% of Men & 75% of women were born in the country ; INCORRECT

Similarly, {E} says the same.

theCodeToGMAT wrote:{B} 98% of Men & 75% of women, who were born .. --> this gives the meaning that 98% of Men & 75% of women were born in the country ; INCORRECT

Similarly, {E} says the same.

this is not the valid reason to eliminate E and B ."who" can never refer to percentages !! "who" will always refer to people .hence the distinction that u have made is not valid .

AnjaliOberoi wrote:The first detailed study of magpie attacks in Australia indicates that by the time they had reached adulthood, 98 percent of men and 75 percent of women born in country have been attacked by the birds.
a) by the time they had reached adulthood, 98 percent of men and 75 percent of women born in country have been attacked by the birds.
b) by the time they reach adulthood, 98 percent of men and 75 percent of women, who were born in the country, had been attacked by birds.
c) by the time they reach adulthood, 98 percent of men and 75 percent of the women born in the country had been attacked by the birds.
d) 98 percent of the men and 75 percent of the women that were born in the country were attacked by the birds by the time they reach adulthood.
e) 98 percent of men and 75 percent of women who were born in the country, by the time they reached adulthood had been attacked by birds

OA is C, can anyone explain why B and E is wrong..

C as it stands now cannot be correct
C should have been : by the time they reached adulthood, 98 percent of men and 75 percent of the women born in the country had been attacked by the birds

reason -->to use past perfect we need another past event!

the reason as why E is wrong because it is difficult to parse
E says : 98 percent of men and 75 percent of women who were born in the country, by the time they reached adulthood had been attacked by birds

in E the expression "by the time they reached" is used as modifier .now u cannot set off a modifier in the middle of the sentence with just one comma .either we have to block it off with 2 commas or with no comma at all .in fact it is really difficult to parse E as is written

i feel E would have made a contender had E been written as follows:

E : 98 percent of men and 75 percent of women who were born in the country, by the time they reached adulthood, had been attacked by birds

i see u have also asked as why B is wrong
B says : by the time they reach adulthood, 98 percent of men and 75 percent of women, who were born in the country, had been attacked by birds.

well logically the present tense "by the time they reach adulthood" is just plain wrong in this contest .you can use simple present only for facts that hold true always !! this is not the case here
for instance u can say : sun rises in the east

also if u look at B grammatically then it makes no sense to use simple present "they reach adulthood" with past perfect "had been attacked by birds"

i will appreciate if u can tell me the source because in the given option even C stands wrong .

It is very important to understand the intended meaning of the sentence to ascertain the timeline of the events. The first detailed study of magpie attacks in Australia suggests that by the time 98% of men and 75% of women reached adulthood, they had already been attacked by the bird.

Notice that the sentence says that men and women had already been attacked by the bird even before they reached adulthood. This means that they got attacked first and then they reached adulthood. Now this can be reported in two ways:
a. "by the time they reach adulthood, 98% of men and 75% of women have been attacked by the birds." (Reported in Present context)
b. "by the time they reached adulthood, 98% of men and 75% of women had been attacked by the birds." (Reported in Past context)

Error Analysis:
1. This sentence uses past perfect tense for the event that took place later and present perfect tense for the event that took place earlier. In order to establish the correct sequencing, we must use past perfect for the event that took place earlier, that is men and women being attacked, and simple past tense for the event that took place later, that is they reaching adulthood.

POE:

Choice A: by the time they had reached adulthood, 98 percent of men and 75 percent of women born in the country have been attacked by the birds. Incorrect for the verb tense error discussed above.

Choice B: by the time they reach adulthood, 98 percent of men and 75 percent of women, who were born in the country, had been attacked by the birds. Incorrect. This choice repeats the verb tense error by using simple present tense for the event that took place later when past perfect has been correctly used for the earlier event.

Choice C: by the time they reached adulthood, 98 percent of men and 75 percent of women born in the country had been attacked by the birds. Correct. The verb tense error has been corrected here.

Choice D: 98 percent of men and 75 percent of women that were born in the country were attacked by the birds by the time they reach adulthood. Incorrect.
a. "that" cannot be used to refer to "men and women".
b. "reach" is not written in the correct verb tense.

Choice E: 98 percent of men and 75 percent of women who were born in the country, by the time they reached adulthood had been attacked by the birds. Incorrect. We Have modifier ambiguity in this choice. Notice that "by the time they reached adulthood" is placed little awkwardly that makes it ambiguous that which entity it's modifying. It seems as if it is modifying "who were born in the country". This modifier should have a comma after adulthood to do away with this ambiguity.

PS - Pronoun "they" in Choices A, B, C and E refers to "men and women" because only these men and women reached adulthood. There is no other antecedent "they" can logically refer to.

takeaway
1. Use past perfect for the event that took place earlier and simple past for the event that took place later.
2. Use the correct combination of verb tenses depending upon the context of the sentence.
3. There should not be any ambiguity in modifier reference.

https://gmatclub.com/forum/the-first-det ... 77464.html