First, we'll want to write out the equation

then reduce what we can

so this means n can equal any whole number between 9 4/9 & 12, which gives us the options of {10,11}
You can determine the actual markdown by changing the percentage to a decimal then multiplying it by the price to find your mark down.
Step-by-step explanation:
Mr.Josol : what will be the height of the ball after 2 seconds?
You would find the sign if the signs are not the same if you are dividing or multiplying its negitve if its the same its positive