Carcass wrote:
The solution provided is perfect
Q3: If South America has a population of 368 mln, then the total population is 368/0.079 = 4658.23. Then, the population of Africa is 4658.23*0.106=493.77 that is rounded to 494 mln. Answer A!
SA had 7.9 % of the entire number, which is X
So, 7.9 %
368=0.079 x
x= 368/0.079 = 4658.23
Now, Africa is 4658.23*0.106=493.77
Hope now is more clear.
But this is the type of question ETS would never write. If we use .08 and 0.1 instead of .079 and 0.106, we get very close to option 470. So, the practice material ends up inducing us to eschew estimation altogether... in the test, estimation plays a big role on time management... Anyway...