Question

45 is subtracted from a number of two digits, then the digits of the number change their positions among themselves. The number digit of the number is 5 less than the tens digit. What is the original number?

Answer 1

Let the no. be 10x+y

10x+y-45=10y+x

=)9x-9y=45

=)x-y=5

y+5=x

=)x-y=5

Since both the equations are the same, the no. is 0.