10^5 = 100 000 --> 10 followed with 4 zeros When substracting one : 9 followed by 4 9's (99999) 10^10 = 10 000 000 000 --> 10 followed with 9 zeros When susbtrasting one : 9 followed by 9 9's (9 999 999 999) 10^50 = 10 followed with 49 zeros When substracting 1 : 9 followed by 49 9's Then, by susbtr...

Many thanks ... It looks so crystal clear once you have the solution

Do you have a "special strategy" to find these sets of numbers ? I'm always encoutering problems when dealing with those types of problems (the list type).

IMO : B You can rewrite the inequality by dividing both sides of the equation by x : y > 1/y 1 tells you that: both x and y are positive, or both x & y are negatives. INSUFFICIENT 2 tells you that y < 0. SUFFICIENT Let's try for dfferent values of y : y = -2 Is -2 > -1/2 ? No y = -10000 Is - 100...

By picking numbers :

800 at 8% is 64, thus leaving 1200 at 10%, which is 120.

120 - 64 = 56

Thanks for the answer !

However, isn't it supposed to be :

2^(4-1)^2 = 2^(3)^2 = 2^(3*2) = 2^6 ?

I'm confused !


EDIT :

Ok, think I got it, it's coming from the bracket :

(2^(4-1))^2 = 2^6
2^(4-1)^2 = 2^9

Thanks again

Powers

Hello guys,

This one had me wondering, as I thought it was an easy one (the first question I had on the GMAT prep Cat):

2^(4-1)^2 / 2^(3-2) = ?

2^8
2^7
2^6
2^5
2^4

I thought this was D, but the OA is A.

Can someone explain ?

Geometry / Circle / Graphic approach

Hello guys,

See the attachment for the subject !

OA is circled

I think your mistake is to think of the 15% as being 15% of 207, when the 15% are in fact 15% of the price without the gratuity.

You are looking for X :

X + 15/100 * X = 207

I would advise you to pick numbers :

12 * 15 = 180

15 / 100 * 180 = 27

180 + 27 = 207