Question

A variable name in certain computer language must be either an alphabet or an alphabet followed by a decimal digit. The total number of different variable names that can exist in that language is equal to

• A. $280$
• B. $290$
• C. $286$
• D. $296$

Answer 1

The correct option is C $286$

Number of variable names if only alphabet is used is $26$.
Now, if every alphabet is followed by decimal digit, then Number of variable names are $26\times 10=260$

Hence, total number of different variable names possible are
$26+260=286$