When naming organic compounds, there are strict rules regarding punctuation.

1. A comma is used to separate two numbers.

2. A hyphen is used to separate a number from a letter.

Add hyphens and/or commas to this name as appropriate.

3ethyl2methylhexane

3-ethyl-2-methylhexane

Explanation:

The IUPAC nomenclature of alkanes are given as follows:

Select the longest possible carbon chain. For the number of carbon atom, we add prefix as 'meth' for 1, 'eth' for 2, 'prop' for 3, 'but' for 4, 'pent' for 5, 'hex' for 6, 'sept' for 7, 'oct' for 8, 'nona' for 9 and 'deca' for 10. A suffix '-ane' is added at the end of the name. If two of more similar alkyl groups are present, then the words 'di', 'tri' 'tetra' and so on are used to specify the number of times these alkyl groups appear in the chain. The numbers are separated by the comma and the number and the letter are separated by the hyphen.

Hence, the given name is: - 3ethyl2methylhexane

By using the last rule, the correct name is:-

3-ethyl-2-methylhexane