1)
CH3-CH(CH3) - CH2-CH2-CH2-CH3
C7H16
2)
CH3-CH2-C(CH3)(C2H5)-CH2-CH3
C8H18
3)
CH3-CH(CH3)-CH(CH3)-CH(CH3)-CH2-CH3
C9H20
1)
CH3-CH(CH3) - CH2-CH2-CH2-CH3
C7H16
2)
CH3-CH2-C(CH3)(C2H5)-CH2-CH3
C8H18
3)
CH3-CH(CH3)-CH(CH3)-CH(CH3)-CH2-CH3
C9H20