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प्रश्न
How many words can be formed from the letters of the word 'SUNDAY'? How many of these begin with D?
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उत्तर
Total number of words that can be formed with the letters of the word SUNDAY = 6! = 720
Fixing the first letter as D:
Number of arrangements of the remaining 5 letters, taken 5 at a time = 5! = 120
Number of words with the starting letter D = 120
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