Question

which of this is a rational number
a)7+root3
b)3 root 3×root 27
c)4/root3
d)none of these​

Answer 1

option b is correct answer

Answer 2

Answer:

option b)

Step-by-step explanation:

$a)7+\sqrt{3} \ \ - \ irrational \\\\ b)3\sqrt{3} \times \sqrt{27} \\ =3\sqrt{3} \times \sqrt{9\times3 } \\ =3\sqrt{3} \times \sqrt{3^2 \times 3}\\=3\sqrt{3} \times 3\sqrt{3}\\=9(3)\\=27 \ \ - \ rational$

$\\ \\ c)\frac{4}{\sqrt{3} } \\\\ rationalising \ factor=\sqrt{3} \\\\ =\frac{4}{\sqrt{3} } \times \frac{\sqrt{3} }{\sqrt{3} } \\\\ =\frac{4\sqrt{3} }{3 } \ \ - \ irrational$