langtuprovn2007 wrote:

oh great I cannot even think about that solution ! thank you very much ! Can you help me with another problems

n is an integer between 2 and 84. What is the value of n?

(1) The square root of n is divisible by 5.

(2) n is both the square and the cube of an integer.

Tks :D

Answer would be "D"

Statement 1:

n should be a perfect square as squareroot of n is divisible by 5

So perfect square between 2 and 84 are 4,9,16,25,36,49,64,81

Now only sqrt(25) is divisible by 5, hence

sufficientStatement 2:

Perfect cube between 2 and 84 are : 8,27,64..

Perfect squares are: 4,9,16,25,36,49,64,81

Hence n= 64.

Sufficient.