Let \(a_{1},a_{2},\ldots.,a_{n}\) be in A.P. If \(a_{5} = 2a_{7}\) and \(a_{11} = 18\), then \(12\left( \frac{1}{\sqrt{a_{10}} + \sqrt{a_{11}}} + \frac{1}{\sqrt{a_{11}} + \sqrt{a_{12}}} + \ldots.. + \frac{1}{\sqrt{a_{17}} + \sqrt{a_{18}}} \right)\) is equal to