From 1,2,3,4,5,6,7 how many 6 digit number combinations can you find without…
2026
From 1,2,3,4,5,6,7 how many 6 digit number combinations can you find without reputation and second last digit must be even ?
- A.
1620
- B.
2160
- C.
1080
- D.
2700
Attempted by 364 students.
Show answer & explanation
Correct answer: B
Answer: 2160
Explanation:
Choose the second-last digit (the 5th position) to be even. There are 3 choices: 2, 4, or 6.
After fixing that digit, 6 digits remain. Fill the other 5 positions (the first four and the last) with distinct digits from these 6: number of ways = 6 × 5 × 4 × 3 × 2 = 720.
Total ways = 3 × 720 = 2160.
Therefore, 2160 six-digit numbers can be formed from digits 1–7 without repetition when the second-last digit is even.