There are twelve instances where the integers from 1 to 200 contain the digit 1 at least twice:-
11,101,110,111,121,131,141,151,161,171,181,191.
4
50
None. The sum of one digit can't be twice the size of the digit.
216.
A proper 2-digit number (which must be smaller than 100) cannot be twice a 10-digit number (which must be larger than 999,999,999).
4
It is prime. When multiplied by the integers 1 to 9, the value is simply that digit twice.
Greatest: 989949 Least: 100000
The largest six digit number period is 999999. The largest number meeting your criteria is 998949.
They are both evenThey each have 2 digitsFor both numbers the second digit is twice the first digitThey are both positive integers
50
None. The sum of one digit can't be twice the size of the digit.
The units digit of a two digit number exceeds twice the tens digit by 1. Find the number if the sum of its digits is 10.
216.
5 and 10
A proper 2-digit number (which must be smaller than 100) cannot be twice a 10-digit number (which must be larger than 999,999,999).
216