Write all whole numbers between 100 and 200 which do not change if the digits are written in reverse order.

A whole number which does not change when its digits are written in reverse order is called a palindrome.

A 3-digit palindrome has the form 'aba', where the hundreds digit and the units digit are the same.

For the number to lie between 100 and 200, the hundreds digit must be 1, so the units digit must also be 1.

The tens digit can be any digit from 0 to 9.

Hence, the required whole numbers are:

101, 111, 121, 131, 141, 151, 161, 171, 181, 191.