Answer:
$99
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