Question

The average of the two digit numbers, which remain the same when the digits interchange their positions is:

• A. $33$
• B. $44$
• C. $55$
• D. $66$

Answer 1

The correct option is C $55$

Average is the sum of the data values divided by the total number of data values.

The two digit numbers which remain same when the digits interchange their position are $11,22,33,44,55,66,77,88,99$

Therefore, average $=\frac{11+22+33+44+55+66+77+88+99}{9}$

$=\frac{495}{9}=55$