A coin with heads on one side and tails on the other has a 1/2 probabi

Take the task of listing possible outcomes and break it into stages.

Stage 1: Select an outcome for the 1st flip
The flip can be heads or tails.
So, we can complete stage 1 in 2 ways

Stage 2: Select an outcome for the 2nd flip
The flip can be heads or tails.
So, we can complete stage 2 in 2 ways

Stage 3: Select an outcome for the 3rd flip
We can complete this stage in 2 ways

Stage 4: Select an outcome for the 4th flip
We can complete this stage in 2 ways

Stage 5: Select an outcome for the LAST flip
This flip MUST be heads.
So, we can complete this stage in 1 way


By the Fundamental Counting Principle (FCP), we can complete all 6 stages (and thus list possible outcomes) in (2)(2)(2)(2)(1) ways (= 16 ways)

Answer: E

Note: the FCP can be used to solve the MAJORITY of counting questions on the GMAT. So, be sure to learn it.

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