What number has 2 digits and when a decimal point is placed between them, the resulting number is the average of digits in the 2 digit number??
If the number is ab, then a.b = (a+b)/2
That is,
a + b/10 = (a+b)/2
10a+b = 5a+5b
5a=4b
Given the one-digit values of a and b, the number must be 45