Answer:
(a) 3-ethylpentane (because the longest chain is 5 carbon atoms, and ethyl is positioned at the 3rd carbon atom)
(b) 1, 2-dimethylbutane (because two methyl is positioned at the 2nd and 3rd carbon atom)
(c) 3, 4-dimethylhexane (the longest chain here is 6 carbon atoms, and two methyl is positioned at the 3rd and 4rd carbon atom)
(d) 3-methyl 4-ethylhexane ( the longest chain is 6 carbon atoms, one methyl is positioned at the 3rd carbon atom while one ethyl is positioned at the 4rd carbon atom)
(e) and (f) are similar to the question before... and I dunno how to (g) and (h) cuz I haven't learned it
Hope that you are able to answer the rest!!