Question

The sum of the digital of two digit number is 11 . The number is less than the number obtained by interchanging the digit by 9 . Find the number .

Answer 1

Let tensplace digit =x
unitplace digit=y
The numbers =10x+y
If obtained by reversing the dogit= 10y+x
Given,
10x+y-(10y+x)=9
10x+y-10y-x=9
9x-9y=9
Deviding each term with 9 we get,
x-y=1.........1
Given, x+y=11.........2
Add eqn 1&2
2x=12
x=6
Put x=6 in eqn 2
y=11-6
y=5
Therefore the numbers= 10x+y
=10×6+5
=65
Hope you understand
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