If a = 5, b = -2 and c = -3, a³ + b³ + c³ is equal to :

1. -90

2. 90

3. 60

4. -60

If x + 3y + 2z = 0, the value of x³ + 27y³ + 8z³ is :

1. 9xyz

2. 6xyz

3. 18xyz

4. xyz

Find the cube of 3a - 2b.