ABC26GN5286 · Permutations and Combinations

Subject: General Aptitude · Chapter: Permutations and Combinations · Exam: 2006 · Marks: · Difficulty:

In how many different ways can the letters of the word RIDDLED be arranged?

(a)840

(b)1680

(c)2520

(d)5040

(e)None of these

Answer

Answer (as printed): A

Explanation

The given word contains 7 letters of which D is taken 3 times. 7 7×6×5×4× 3 ∴ Required number of ways = = 3 3 = (7 × 6 × 5 × 4) = 840.

Explanation as extracted from the printed page; notation may be imperfect.