\(A=\dfrac{\sqrt{60}}{\sqrt{15}}=\sqrt{\dfrac{60}{15}}=\sqrt{4}=2\)
\(B=\sqrt{\dfrac{72}{15}}:\sqrt{\dfrac{2}{15}}=\sqrt{\dfrac{72}{15}}\cdot\sqrt{\dfrac{15}{2}}=\sqrt{\dfrac{72}{2}}=\sqrt{36}=6\)
\(C=\left(\sqrt{3}+\sqrt{2}\right)\cdot\left(\sqrt{2}-\sqrt{3}\right)=\left(\sqrt{2}\right)^2-\left(\sqrt{3}\right)^2=2-3=-1\)