Q58 / 160 · TS EAMCET 2024 (09 May Shift 1) · Mathematics
The number of all possible combinations of 4 letters which are taken from the letters of the word ACCOMMODATION is
- Correct answerA167
- B161
- C160
- D157
Solution
$A-2, C-2, O-3, M-2, D-1, T-1, I-1, N-1$
The following cases arise :
3 alike and one different - No. of ways is 7 .
2 alike and 2 alike - No. of ways $={ }^4 C_2=6$
2 alike, 2 different $={ }^4 C_1 \times{ }^7 C_2=4 \times 21=84$
All 4 different $={ }^8 C_4=70$
Total no. of ways $=167$.
Hence, the correct answer is option: 'A'.