Question

The number of seven letter words that can be formed by using the letters of the word $SUCCESS$ that the two $C$ are together but no two $S$ are together is

• A. $24$
• B. $18$
• C. $54$
• D. none of these

Answer 1

The correct option is B $18$

using the letters of the word $SUCCESS$ that the two $C$ are together but no two $S$ are together

let two C's be 1 unit

$\therefore$ no. of ways $=\frac{6!}{4!}=30$

We have to put 1 letter between one S

So, No of ways$=2\times 3!=12$

No. of ways=30-12=18