Question

the sum of a two digit number is 12 if 18 is added to the number the digits are reversed what is the original number​

Answer 1

Let tens place digit be x
So, units place digit= 12- x
Original no.= 10x+12-x= 9x+12
By reversing the digits,
New no.= 10(12-x)+x= 120-10x+x= 120- 9x
According to the question,
9x+12+18= 120-9x
9x+30= 120- 9x
18x= 90
X= 5
So original no.= 9x+12= 45+12= 57