If a : b = 3 : $\sqrt{5}$, then the value of (2a + b) : (3a - 2b) is :

$\frac{1}{64}(64 + 21\sqrt{5})$ $\frac{1}{62}(64 + 21\sqrt{5})$ $\frac{1}{63}(64 + 21\sqrt{5})$ $\frac{1}{61}(64 + 21\sqrt{5})$

$\frac{1}{61}(64 + 21\sqrt{5})$

Here, A : B 3 : \(\sqrt { 5}\) ⇒ 3k , k\(\sqrt { 5}\) ⇒ 2a + b = 6k + k\(\sqrt { 5}\) ⇒ 3a - 2b = 9k - 2k\(\sqrt { 5}\) ⇒ ( 6k + k\(\sqrt { 5}\)) : (9k - 2k\(\sqrt { 5}\)) ⇒ ( 6k + k\(\sqrt { 5}\))(9k - 2k\(\sqrt { 5}\)) : (\( {9 }^{2 } \) - 20) ⇒ (64 + 21\(\sqrt { 5}\))\(\frac{1}{61}\)