Question

Sum of digits of a 2 digit number is 8. When 18 is added to the no, the digits gets reversed. What is the no

Answer 1

Let the tens digit be x and ones digit be y

Thus original number is 10x+y

Given that x+y=8--------(1)

No. Obtained when digits are reversed =10y+x

Also given that 10x+y+18=10y+x

10x+y-10y-x=-18

9x-9y=-18

9(x-y)=-18

x-y=-18/9

x-y=-2-------(2)

Adding(1) and (2)

x+y=8

x-y=-2

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2x=6

x=6/2. x=3

Substitute x=3 in (1)

x+y=8

3+y=8

y=8-3. y=5

Hence x=3 and y=5

Hope it works