A population of game ducks at a western lake contains 55 males to every 45 females, while a population of game ducks at an eastern lake contains 65 males for every 35 females. Among those ducks that have not yet bred there are only slightly more males than females, but among older ducks the number of males greatly exceeds the number of females. Because there are appreciably more males among adult ducks than among young ducks, we can infer that the greater the disparity in overall sex ratios, the greater the percentage of older male ducks in the population.
Which one of the following can be inferred from the passage?
(A) The population of game duck at the western lake contains a lower percentage of adult males than the population at the eastern lake contains.
(B) The population of game duck at the eastern lake contains a higher percentage of nonadult game ducks than the population at the western lake contains.
(C) The total number of male game ducks is higher in the eastern lake’s population than in the western lake population.
(D) The number of nonadult ducks hatched in a breeding season is higher in the eastern lake’s population than in the western lake’s population.
(E) Adult female game ducks outnumber nonadult female game ducks in the eastern lake’s population.
Please explain your answers.
A this one is super tricky.. will try to explain
western: 55M to 45M
eastern: 65M to 35M
non breeding ducks M > F slightly
older ducks: M > F greatly
stem says that "the greater the disparity in overall sex ratios, the greater the percentage of older male ducks in the population." this means that for the eastern lake, there is a higher percentage of older male ducks.
looking at answer choices and how i eliminated:
A) this is exactly what is given to us, correct (except saying the other side)
B) we do not know if the eastern lake contains higher percentage of non-adult
ducks than the western. older MALE ducks yes but we do not know about the other non-adult males
C) we know that eastern has higher percentage
of adult male ducks but we do not know if eastern has a higher total number
of male ducks than the western
D) nothing in the argument talks about the breeding season
E) stem says nothing about the female count relationship