OpenStax, Algebra and Trigonometry 2e §13.5 Counting Principles · Exercise 19 · Combinatorics · Permutations & combinations

Counting Principles · Exercise 19

Determine whether to use the Addition Principle or the Multiplication Principle. Then perform the calculations.

How many two-letter strings—the first letter from $A$ and the second letter from $B —$ can be formed from the sets $A = {b, c, d}$ and $B = {a, e, i, o, u} ?$

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OpenStax, Algebra and Trigonometry 2e · §13.5 Counting Principles · Exercise 19

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