vladik210 wrote:

Hi,

So finally I started studying for my GMAT which I will take in summer.

I began with

Manhattan GMAT 2007 (Number properties) as it was suggested on the forum. My first question is about exponents.

On page 51, the

MGMAT says the following:

5^1 = 5

5^2 = 25 Increased by 20

5^3 = 125 Increased by 100

5^4 = 625

Increased by 500Now, my primary language is not English but why is 5^4 (aka 625) increased by 500?

Why can't we say that it increased by 620? I mean that why can't we start counting from the 5^1?Also, in Russian there are two ways how to say the number has increased:

a. Arithmetically

b. Geometrically

In the example of 5^4 compared to 5^1, we can say that

a. 5^1 has increased by 620 arithmetically (that is 620 has been added)

b. 5^1 has increased by 125 geometrically (that is 5 has been multiplied by 125)

However, English language does not specify when somebody says that "Number A has increased by B". Naturally, I start thinking that a geometrical progression is being used. Nevertheless, I found out that by default the expression "Number A has increased by B" means the addition of the B.

So, what are the common ways for GMAT to ask questions when multiplication (and not addition) is involved?Thanks.

5^1 = 5

5^2 = 25 Increased by 20

5^3 = 125 Increased by 100

5^4 = 625 Increased by 500

Now, my primary language is not English but why is 5^4 (aka 625) increased by 500?because

with respect to 5, 25 increased by 20, and

with respect to 25, 125 increased by 100, and

with respect to 125, 625 increased by 500

However, English language does not specify when somebody says that "Number A has increased by B". Naturally, I start thinking that a geometrical progression is being used. Nevertheless, I found out that by default the expression "Number A has increased by B" means the addition of the B. Number A has increased by B -- as long as B is a number, it refers to addition

if B is rate, like A increased by 2 times, then it is multiplication --