A $100 MP3 player is marked up by 10% and then marked down by 10%. What is that final price?

$99

Step-by-step explanation:

MP3 Player: $100

10% Mark up: $100/10= 10

Therefore, Mark-Up Price: $100+$10= $110

This was then Marked down by 10%.

Therefore,

10% Marked down: $110/10= $11

(We then take this away from the marked up price)

Hence, Final Price : $110-$11= $99

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204