Answer
18
Work Step by Step
ALTERNATIVE 1: select single package type
....... Step 1: select CD type ... 2 choices
....... Step 2: select color ... 5 choices
(Total Alternative 1: 2(5)=10)
ALTERNATIVE 2: select spindle of 50 package type
....... Step 1: select CD type ... 2 choices
....... Step 2: select color ... 2 choices
(Total Alternative 3: 2(2)=4)
ALTERNATIVE 3: select spindle of 100 package type
....... Step 1: select CD type ... 2 choices
....... Step 2: select color ... 2 choices
(Total Alternative 3: 2(2)=4)
TOTAL=... addition principle, 3 alternatives...=10+4+4=18