There are 6 multiple choice questions in an examination.
Question:

There are 6 multiple choice questions in an examination. How many sequences of answers are possible, if the first three questions have 4 choices each and the next three have 2 each?

Solution:

Number of ways of answering the first three questions = 4 each

Number of ways of answering the remaining three questions = 2 each

$\therefore$ Total number of ways of answering all the questions $=4 \times 4 \times 4 \times 2 \times 2 \times 2=512$