Answer
The formula of the compound is:
$3-ethyl-2,2,6-trimethylheptane$
Work Step by Step
The longest carbon chain has 7 carbon atoms (-hept). There are 3 methyl substituents, two on position 2 and one on position 6. There is an ethyl substituent on position 3. Listing the substituents in alphabetical order, the formula of the compound is:
$3-ethyl-2,2,6-trimethylheptane$