Question

Which of the following number has same unit digit as its cube?

• A. ${122}^3$
• B. ${168}^3$
• C. ${137}^3$
• D. ${184}^3$

Answer 1

Answer: (D)

${184}^3$

Here,

${122}^3$:

The number ends in $2$ and $2^3=8$ so its cube will end in $8$.

${168}^3$:

The number ends in $8$ and $8^3=512$ so its cube will end in $2$.

${137}^3$:

The number ends in $7$ and $7^3=343$ so its cube will end in $3$.

${184}^3$:

The number ends in $4$ and $6^3=64$ so its cube will end in $4$.

Therefore, option $D$ is correct.