DI question on test 1

[arijitpal2009]

This is about the problem no 15 in test 1 on math section 2



I had answer B but it is given the the answer is none of this. There is also an explanation given. But I think it is not a set problem. I approached the problem in the following way:

((1/2* x)(15/100)/x)*100%= 7.5

Here x= 108 hundred thousands

I can't understand what is wrong with my approach, its pretty straightforward.

[tommywallach]

Hey Arjit,

I have no idea what your equation is there. This is a percent change question. There's no need for x, because nothing is unknown.

The equation for percent change is difference/original.

2001 population: 282,000
2008 population: 301,500
(I just eyeballed these myself)

Difference = 301,500 - 282,000 = 19,500
Original = 282,000

19,500/282,000 =.069 --> 7%

This is THE correct way to do the question.

-t