In how many different ways can the letters of the word DISPLAY be arranged?
A
720
B
1140
C
2520
D
5040
E
None of these
Correct Answer: 5040
The given word contains 7 letters, all different .∴ Required number of ways
$$\eqalign{ & {}^7{P_7} = 7! \cr & = \left( {7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1} \right) \cr & = 5040 \cr} $$