Answer
a. 2-methylpropene.
b. 4-bromo-2-pentyne
c. 4-ethylcyclopentene
d. 4-ethyl-2-hexene
Work Step by Step
1. Identify the largest chain of carbons.
2. Number in a way that the double/triple bound gets the lowest number possible.
3. Name and number the substituents.
4. Don't forget to number the position of the double/triple bond if necessary.