Name so that the C=C carbons are 1 and 2 and the substituents have the lowest possible numbers.
The new names are given below. If you click here you will see the structures and the names.
(15.15)(d) - New IUPAC name is 3-ethyl-2-methylcyclohexene
(15.16)(b) - New IUPAC name is 2,3-dimethylcyclopentene
(15.16)(d) - New IUPAC name is 2,3-diethylcyclohexene