Question

n a two digit number the units digiy is twice the tens digit . if 27 is added to the no the digits interchange their places . find the number

Answer 1

Let the units digit be y and tens digit be x,then the equations are,
Y=2x and 10x+y+27=10y+x
Substituting value of y in equation two,we have,
10x+2x+27=10(2x)+x
That is x=3
Substituting x value in first equation,
We have,y=6
Therefore the number is 36