If it is 1,1,3,3 tetra methyl. You should count the longest carbon chain then. First carbon has has two methyl and third carbon has two methyl. Including thst middle carbon. The longest chain should be a 5 carbon chain . Should be 1,3 dimethyl. Hope that makes sense
If it is 1,1,3,3 tetra methyl. You should count the longest carbon chain then. First carbon has has two methyl and third carbon has two methyl. Including thst middle carbon. The longest chain should be a 5 carbon chain . Should be 1,3 dimethyl. Hope that makes sense