Answer:
Isopropylbenzene
Step-by-step explanation:
If you draw the structure, you can see that there are two methyl groups and in between there.
Adjacent to CH3, there are four neighbouring hydrogens, therefore, n=4+1 = 5. The same is for methyl on other side. For carbon present in benzene ring, there is 2, since there is one hydrogen on benzene per carbon.