crackthegmat2011 wrote:If x and y are integers such that y>x>0 and x raise to power m = y raise to power n, then what is value of m + n ?


1. x is prime number

2. y is not multiple of x.

Answer Should be B,


what is the value of M + N , Given x^m = y^n ( x and y are integers )

1. x is a prime number,, We can Have many value for x and y

LIKE x = 2 and y = 8

2 ^ 6 = 8 ^ 2 M+N = 8

3 ^ 10 = 9 ^ 5 M + N = 15

So insufficient.

2. y is not multiple of x. It means x and y must be Coprime to each other.

and co prime value are equal only for the power of 0

So M + N = 0

So sufficient

Answer B.

goyalsau wrote:

crackthegmat2011 wrote:If x and y are integers such that y>x>0 and x raise to power m = y raise to power n, then what is value of m + n ?


1. x is prime number

2. y is not multiple of x.

Answer Should be B,


what is the value of M + N , Given x^m = y^n ( x and y are integers )

1. x is a prime number,, We can Have many value for x and y

LIKE x = 2 and y = 8

2 ^ 6 = 8 ^ 2 M+N = 8

3 ^ 10 = 9 ^ 5 M + N = 15

So insufficient.

2. y is not multiple of x. It means x and y must be Coprime to each other.

and co prime value are equal only for the power of 0

So M + N = 0

So sufficient

Answer B.

is " y is not multiple of x. It means x and y must be Coprime to each other.

and co prime value are equal only for the power of 0" a rule?
can you please explain more details?

Rahul@gurome wrote:

is " y is not multiple of x. It means x and y must be Coprime to each other.

and co prime value are equal only for the power of 0" a rule?
can you please explain more details?

If y is not a multiple of x, it does not mean that x and y are coprime.
Two integers are said to be coprime if they do not have any common factor apart from 1.
For example take x=18 and y=24. 24 is not a multiple of 18 but they are not coprime because they have a common factor 6 apart from 1.
Similarly take 9 and 20. They are coprime because the only common factor for them is 1.

Thanks Rahul,


y is not multiple of x.

It means we can say that they are different integers,