Pick the different number:
Show answer & explanation
Correct answer: D
Explanation
Check the digits and their sum for each number:
• 234: 2 + 3 + 4 = 9 (Digits used: 2, 3, 4)
• 243: 2 + 4 + 3 = 9 (Digits used: 2, 3, 4)
• 324: 3 + 2 + 4 = 9 (Digits used: 2, 3, 4)
• 312: 3 + 1 + 2 = 6 (Digits used: 1, 2, 3)
Except 312, all other numbers are formed by rearranging the digits 2, 3, and 4 (and have a digit sum of 9).
Therefore, 312 is the odd one out.