Let the number be 10x+y.
Digits of number are x and y.
According to question,
Substituting the value of x,
y²-13y+36=0 [Now, Factorising]
Now, y=4 or y=9
When y=4, x=13-y=13-4=9 and the number becomes 94.
When y=9, x=13-y=13-9=4 and the number becomes 49.
But, no. should be less than 50.
The number is 49 Ans
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