Question 309030
let x be in the ten"s place
Let y be in the units place
x=2y

the number will be 10x+y

10x+y + 10y+X =99
11X+11Y= 99
plug the value of x in the above equation

22y +11 y = 99
33y=99
y= 3
x= 6
The number is 63