Let the ten's digit =x
Then unit's digit =x+3
∴ Original number =10×x+(x+3)=11x+3
Number formed after reversing digits
=10(x+3)+x
=10x+30+x=11x+30According to given condition
11x+3011x+3=74⇒44x+120=77x+21
⇒77x−44x=120−21⇒33x=33⇒x=3
The number =11×3+x=33+3=36