Question

draw the structure of 4-tertbutyl-3-iodoheptane

Answer 1

this is the structure of your question

Answer 2

Answer: As the word root is hept, the longest carbon chain must contain seven carbon atoms. There are two substituents one at carbon number 3 and one at 4. The carbon numbered 3 bears the substituent Iodine and carbon number 4 bears the substituent tert butyl.

The IUPAC name starts from the number of carbon bearing the substituent  followed by the name of the substituent. The substituent which comes first alphabetically is named first. In tert butyl, butyl is not considered in the naming. Then the word root hept comes followed by ane which means all the bonds are single bonds.