Question
Mon August 29, 2011 By:

Find the number.

Expert Reply
Mon August 29, 2011
Please post one query at a time.
Solution to the first question is as follows:
Let the two digit number be 10 x + y
ATQ,   10 x + y = 4(x + y)      ----(i)
             10 x + y = 2 xy           ----(ii)
From (i),    10 x + y = 4 x + 4y
      =>      6x = 3 y  
      =>      2x  =   y                   ----(iii)
Substituting (iii) in (i) :
10 x + 2x = 2x.2x
=> 12x = 4x2
=> 4x2- 12x = 0
=> 4x ( x - 3) = 0
=> x = 0 or x = 3
x = 0 is not permissible
Hence, x = 3
So, (iii) =>  y = 2x = 2. 3 = 6
Therefore , the required number is 10 .3 + 6 = 36
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