## Algebra and Trigonometry 10th Edition

As we are required to calculate the number of configurations, and order doesn't matter, we need to use combinations. This problem is solved by multiplying ($3_{C_{1}}$) ways for amplifiers, ($2_{C_{1}}$) CD players, and ($5_{C_{1}}$) speaker models. So $3_{C_{1}}$*$2_{C_{1}}$*$5_{C_{1}}$= 3*2*5 = 30