$\sqrt{2^{4}}+\sqrt[3]{64}+\sqrt[4]{2^{8}}$ is equal to :
[A]12
[B]16
[C]18
[D]24

12
$\sqrt{2^{4}}+\sqrt[3]{64}+\sqrt[4]{2^{8}}$
$= 2^{4\times \frac{1}{2}}+4^{3\times \frac{1}{3}}+2^{8\times \frac{1}{4}}$
$= 2^{2}+4+2^{2}$
$= 4+4+4 = 12$
Hence option [A] is correct answer.