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 $B = {a, e, i, o, u} ?$

Its source prints no answer for this problem, so there's nothing to check against.

~8 minWritten answer · compare with the solution

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

Stuck? A gentle nudge

No hints for this one.

Something off?

Workspace

Your working

Check your full solution

Upload photos of your handwritten work or a PDF, and Lemma will read it and tell you whether it's right — and where it first goes wrong if not.