What is the IUPAC name of the following compounds?

Question

a)
---CHO
---I
CH3CCH3
---I
---CH2CH3
b)
-----------CH3
-----------I
CH3CHCH2CH2CHCH2CH3
---I
---CH2CH3

Answer 1

I think this is #1 if I've interpreted the spacing correctly.
http://www.chemsynthesis.com/base/chemical-structure-32187.html

I can't interpret the spacing of the second one. Is the top CH3 group on carbon 3 from the left? Is the bottom ethyl group on carbon #2? If so, then it is an octane, specifically,
3,4-dimethyloctane
Check me out on these.