Question

Robert was asked to made a $5$ digit number from the digits $2$ and $4$ such that first digit cannot be $4$. Find the number of such $5$ digit numbers that can be formed .

• A. $10$
• B. $12$
• C. $16$
• D. $18$
• E. None of these

Answer 1

Answer: (C)

$16$

Total $5$ digit numbers $=1\times 2\times 2\times 2\times 2$

$=2^4$

$=16$

$C$ is correct