Question

The units digit of a two-digit number is one-half the tenths digits, when the digits are reverse the new number is 15 more than twice the number. Find the original number.

Answer 1

If the digits are a,b then a = 2b

10b+a = 15+2(10a+b)
10b+2b = 15+2(20b+b)
12b = 15+42b
I suspect a typo. Let's see.
The only possible numbers are 21,42,63,84
The reversed numbers would be 12,24,36,48
In each case, the reversed number is less than the original.