Étude généalogique en anglais : Miller family

Read the description of the Miller family and answer the questions carefully:

'Sarah is the mother of Tom and Emily. Sarah has two siblings: a brother named Mark and a sister named Jane. Mark has one son named Jack. Jane has one daughter named Lily.'

1. What is the precise family relationship between Tom and Jack?
2. What is the precise family relationship between Tom and Lily?
3. Calculate the total number of cousins Tom has. Let $C$ be the number of cousins, where $C = (n_{Mark} \times c_{Mark}) + (n_{Jane} \times c_{Jane})$. Given $n_{Mark} = 1$ (number of Mark's children) and $n_{Jane} = 1$ (number of Jane's children), find the value of $C$.