Hey thanks toothpick for the solutions. I don't know how you guys manage to do them!
A few more questions:
Same booklet Volume 1:
Q4.
Section 1: Q5 (I am stumped! Where do I begin with this one??)
The number of adult smokers in Australia has dropped markedly over the past few decades. While one thrid of the population smoked in 1985, by 1995 the number had shrunk to one quarter. Particularly significant is the drop in numbers for male smokers: down from 72% in 1945 to 27% in 1995. However, the proportion of female smokers has hardly changed over the years (down from 26% in 1945 to 23% in 1996). Whilst the population doubled between 1945 and 1995, the proportion of males to females was about equal over the same period. The Australian population in 1995 was 18 million.
According to this information, which of the following is the best conclusions?
A. In 1985 only about 18% of Australian males were non-smokers.
B. It is likely that in 1985 more than 4 million Australian females smoked.
C. There were actually more male smokers in Australia in 1995 than in 1945.
D. It is reasonable to assume that about 40% of males smoked in Australia in 1985.
a bit late, but I don't think the answer is A as ganges suggested
as said by the question, about 1/3 of population smoked.
also, male population ~ female population, and %female smokers is about 25%
hence, of the 50% female [of total], 25% smoked, i.e. ~12.5% of smokers are females
==> ~20% smokers are males [of total population]
==> ~40% males are smokers [of the 50% male population of total]
==> %non-male-smokers ~ 60%, not 18%
B is also false, assuming population growth is roughly linear
growth in 50 years is 9 million
growth in 10 years (from 85 to 95) is ~2 million
i.e. female population ~8 million in 1985
==> %female smokers = 25% * 8 million ~ 2 million (not 4)
C is false.
72% * 4.5 million (1945) = 36% * 9 million > 27% * 9 million (1995)
which leaves D, and it is fairly reasonable [well, at least within parameters]