Question

Number of $4$ letter words starting with vowel that can be formed using letters of the word ${}^{\prime }CHEMISTR{Y}^{\prime }$ are

• A. $336$
• B. $504$
• C. $672$
• D. $1008$

Answer 1

The correct option is C $672$

${}^{\prime }CHEMISTR{Y}^{\prime }$
The word can be started with either $E$ or $I$.
If the word starts with $E$, then the rest $3$ letters can be arranged as${}^8{P}_3=336$
Similarly, if the word starts with $I$, then the rest $3$ letters can be arranged as${}^8{P}_3=336$
Total words $=2\times 336=672$