mand-y wrote:

arunsanand wrote:

Agree with that...there is no two digit no which is equal to the product of its digits.

here is the link to the post but i don 't understand the approach used

thanks[/u]the link

http://www.gmatclub.com/phpbb/viewtopic ... =remainder
buddy, the problem was misread ..it must be: what is the two-digit number which is twice the product of its digits.

Let's look at the solution provided in the link:

------------

Solution1:Let x be the digit in ten's place and y be the digit in unit's place.

From question stem: 10x + y = 2xy

Therefore, x = y/2(y-5)

Since x and y are digits of a 2-digit number, x and y are positive integers.

So, y must be greater than 5 and also y must be even. Try the first even number greater than 5 => 6

If y = 6, x = 3 --> 2-digit number = 36

-------------

from 10x+y= 2xy --> y must be even coz 2xy and 10x are even

since x=y/2(y-5) --> y must be > 5 coz if y<=5 --> y-5<= 0--> x <=0 coz y/2 is always > 0

=> the bold part.