What's the general formula for an alkane if n is the number of carbon atoms?

Option D  

Explanation:

Alkanes have nothing but carbon and hydrogen bonds, with no double or triple carbon bonds.  Each carbon in the chain will have a unit of CH2, with the other 2 carbon bonds connected to 2 neighboring carbons.  The terminal carbons will have 3 H's each.

So an alkane will have multiple (CH2) groups plus 2 CH3 groups on either end.  If there are n Carbons, there will be 2n Hydrogens plus 2 more for the end carbons.  

i think its 100

i hope this !