jackychamp wrote:

In June 2004, GMAT Club, a community of aspiring MBA students, registered 810 new members. How many members from USA and Canada registered in the month of June 2004?

1. In June 2004, the ratio of new members from USA and Canada, Europe and Asia was 4:3:2

2. In June 2004, none of the members were from locations other than USA and Canada, Europe and Asia

I am not getting the way ratio is given in stmt-1.

can someone please explain the same.

The ans is C. Here is how I approached this Q:

1st ask yourself:

what does the Q tell us?(US+Can)+Others=810

2nd question to ask yourself:

what is needed to find the value of (US+Can)?

to find value for (US+Can) we have to know value for the "Others". Having this in mind we can start evaluating anwer options:

1. if we were sure that (Europe+Asia)=Others than the info provided here would be sufficient. but there could be australia, arctica, and antarctica

2. tells us that in fact (Europe+Asia)=Others i.e. no arctica/antarctica/australia. but we have no #'s to plug in for the "Others" thus insufficient

putting the two together:

(US+Can):E:A=4:3:2

jackychamp here is a trick that should help you to work with ratios:

4:3:2 can be written (4*x):(3*x):(2*x)

so 4x+3x+2x=810 now we just have to solve for x thus sufficient.

How can we be sure that first ratio is of the usa/canada:europe:asia,,,like it could have been possible if it was written, usa or canda and europe and asia