Chapter 12.2, Problem 12.1PP

Are the compounds in each pair constitutional isomers or are they not constitutional isomers of each other?

a. ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}{\text{and CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$

b. ${}^{ }{\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{OH and CH}}_{\text{3}}{\text{OCH}}_{\text{2}}{\text{CH}}_{\text{3}}$