How-many-6-letter-words-in-which-at-least-one-letter-appears-more-than-once-can-be-made-from-the-letters-in-the-word-FLIGHT-

Question Number 133316 by bramlexs22 last updated on 21/Feb/21

How many 6 - letter words in

which at least one letter appears

more than once, can be made from

the letters in the word FLIGHT

Commented by mr W last updated on 21/Feb/21

6^{6} - 6! = 45936

Answered by EDWIN88 last updated on 21/Feb/21

= 6^{6} - 720 = 45 936

Answered by mr W last updated on 22/Feb/21

a n o t h e r w a y :

w o r d s w i t h o n e l e t t e r : C_{1}^{6} \times 1 = 6

w o r d s w i t h t w o l e t t e r s : C_{2}^{6} \times 62 = 930

w o r d s w i t h t h r e e l e t t e r s : C_{3}^{6} \times 540 = 10800

w o r d s w i t h f o u r l e t t e r s : C_{4}^{6} \times 1560 = 23400

w o r d s w i t h f i v e l e t t e r s : C_{5}^{6} \times 1800 = 10800

Σ = 45936

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