First, you should realize that answering this question is going to take more
than merely adding 1,000 percent and 500 percent to get (A), 1,500 percent.
You’re not going to find a word problem on the Math 1 test for which all you
have to do is add two numbers.
This word problem is extra complicated for two reasons. First, the percents
are so huge. You don’t often have to work with “1,000 percent” or “500
percent.” Second, you have a compound percent increase situation, a
situation that’s always trickier than it looks at first.
Call the population of country X at the beginning of the eighteenth century P.
That number increases by 1,000 percent. That is, it goes up by 1,000 percent of
itself. One thousand percent of P means 10P, so if P goes up by that much, it
becomes P + 10P = 11P.
P +(1,000% of P)= P +10P =11PNow the population at the beginning of the nineteenth century is 11P. That
number increases by 500 percent. In other words, on top of 11P, you add 500
increased by 500 percent. By what percent did the population increase
over the two-century period?(A) 1,500%
(B) 1,700%
(C) 4,900%
(D) 5,000%
(E) 6,500%