Building a House. The Jacobsens are planning to build a house in a new development. They can either build the base model offered by the builder or add any of the following options; deck, hot tub, security system, hardwood flooring. How many different variations of the house are possible?

Question

Building a House.  The Jacobsens are planning to build a house in a new development.  They can either build the base model offered by the builder or add any of the following options; deck, hot tub, security system, hardwood flooring.  How many different variations of the house are possible?

anonymous · Answer

how many different variations of the house are possible? that is the most significant point of this question

anonymous · Answer

i.e how many different arrangements (permutations) are possible?
you use the words "they can either build the base model OR add any of the following options(rather than AND). 

you give 4 options, so 4 x 3 x 2 x 1 = 4! = 24 options

anonymous · Answer

that doesn't include the base model!