Question

the digit in the ones place of a number is twice the digits in its tens place. if 9 is added to the number ; the digits of the sum obtained are reverse of those of the number . Find the number with method

Answer 1

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Answer 2

Let the no be 10x+y
Y is in ones place and x is in tens place
According to question the digit in its ones place is twice that of the no which is in tens place
So x=2y
If 9 is added to the no then the new no is 1ox+y +9
And the digits of sum obtained is reversed
So, 10x+y+9 = 10y + x
10×2y+ y + 9 = 10y + 2y
21y+9 = 12y
21y-12y = -9
9y = -9
Y = -1
X= 2y
X= -2
The number is 10x+y
10×-2+-1 = - 21