Answer
30
Work Step by Step
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
