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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?
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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