The largest four digit number which is a perfect cube, is:

Answer: Option B

Answer: Option C

Explanation:

\begin{aligned}
= \sqrt{248+\sqrt{64}}
\end{aligned}

\begin{aligned}
= \sqrt{248+8}
\end{aligned}

\begin{aligned}
= \sqrt{256}
\end{aligned}

\begin{aligned}
= 16
\end{aligned}

Answer: Option C

Answer: Option B

Explanation:

\begin{aligned}
=> \sqrt{81} + \sqrt{0.81} = 10.09 - X
\end{aligned}

\begin{aligned}
=> 9 + 0.9 = 10.09 - X
\end{aligned}

\begin{aligned}
=> X = 10.09 - 9.9 = 0.19
\end{aligned}

Answer: Option C

Explanation:

21*21*21 = 9261