For each of the 165 combinations of women, there are 21 combinations of
men, so the combined number of combinations is 165 × 21 = 3,465. The
answer is (A).
If you’re good at memorizing formulas—if you can master the permutations
and combinations formulas without too much trouble—go ahead and do it.
But all these formulas probably won’t get you more than one right answer on
the Math 1 test, so they don’t deserve a whole lot of time and effort.
Remember that most calculators will compute permutations and
combinations for you.
PROBABILITY
To answer a probability question, you need to know not only how to use the
general probability formula, but also how to deal with multiple probabilities
and probabilities that events will not occur. You have a little bit of everything
in Example 10.