How many words with or without meaning, can be formed by using all the letters of the word "DELHI", using each letter exactly once?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 120
Note: It seems that there is a mistake in the original NTA paper, which prints Option (1) as 12. To arrive at the NTA answer, it should read 120, the number of arrangements of the five letters, and it is so shown here, as explained below.
DELHI has 5 different letters, and each word uses all of them once, so every word is an arrangement of 5 different things, counted by 5! (5 factorial).
The first place can take any of the 5 letters, the second any of the remaining 4, and so on.
Number of words \(=5\times4\times3\times2\times1=\) 120