Question

PERMUTATIONS & COMBINATIONS
122. The number of four letter words that can
be formed using the letters of the word
BARRACK is
(JEE Online-2018)
1) 144 2) 120 3) 264 4) 270​

Answer 1

Answer: 4) 270

Step-by-step explanation: Take the cases and add them,

∴ number of four-letter words that can be formed=120+72+72+6=270