Question

in two digit number the digit at unit place is 1 less than twice the digit at the tens place .if the digit at unit place and tens place are interchanged the difference between the new and the original number is less than the original number by 20 the original number is​

Answer 1

Answer:

Let the ten's digit be x. Then, unit's digit = 2x + 1.

[10x + (2x + 1)] - [{10 (2x + 1) + x} - {10x + (2x + 1)}] = 1

<=> (12x + 1) - (9x + 9) = 1 <=> 3x = 9, x = 3.

So, ten's digit = 3 and unit's digit = 7. Hence, original number = 37.