Let $S=\{a,b,c\}\;$ and$\;T = \{1,2,3\}$. Find the inverse of the following function $F$ from $S$ to $T$, if it exists - $$\;\; F=\{(a,3), (b,2), (c,1)\}$$

Question

Note: This is part 1 of a 2 part question, split as 2 separate questions here.