A. 16
B. 32
C. 64
D. 128
The required number of ways can be formed as (1 black and 2 non-black) or (2 black and 1 non-black) or (3 black)
=> Required number of ways = (3C1 x 6C2) + (3C2 x 6C1) + (3C3)
= (45 + 18 + 1)
= 64
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How many 4-letter words with or without meaning, can be formed out of the letters of the word, LOGARITHMS, if repetition of letters is not allowed?
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