2022 TJC J1 MYE Q2

The vectors \(\mathbf{a}\),\(\mathbf{b}\) and \(\mathbf{c}\) are unit vectors such that the angle between \(\mathbf{a}\) and \(\mathbf{b}\) is \({{30}^{\circ }}\) and the angle between \(\mathbf{a}\times \mathbf{b}\) and \(\mathbf{c}\) is \({{60}^{\circ }}\). Find the value of \(\left( \mathbf{a}+\mathbf{b}+\mathbf{c} \right)\cdot \left( \mathbf{a}\times \mathbf{b} \right)\).[5]