Three of the following four numbers are alike in a certain way and one is different. Choose the number that does not belong to the group.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 6919
Check whether each number is a perfect cube (a number multiplied by itself three times).
Option (1) 1728 — \( 12 \times 12 \times 12 = 1728 \): a perfect cube.
Option (2) 6919 — \( 19^3 = 6859 \) and \( 20^3 = 8000 \); 6919 lies between them, so it is not a perfect cube.
Option (3) 5832 — \( 18 \times 18 \times 18 = 5832 \): a perfect cube.
Option (4) 6859 — \( 19 \times 19 \times 19 = 6859 \): a perfect cube.
1728, 5832 and 6859 are perfect cubes; 6919 is not, so 6919 is the odd one out.