Markup means they sell it for that percentage more than they bought it for. First let's calculate how much they will mark it up for:

Convert 87% into a decimal(87/100):

Multiply:

This is how much they'll mark it up, now let's add it to how much they bought it for to find out the selling price:
A = P(1 +r/n)^nt
P = 500
r = 3.2% = 0.032
n = 1
t = 10
A = 500(1 + 0.032)^10
A = $685.12
a + b = 88 <span>
<span>
</span><span>ab = y
</span><span>
</span><span>a = 88 - b
</span><span>
</span><span>y = (88 - b)*b
</span>
<span>y = -b^2 + 88b
</span><span>
</span><span>Take the derivative and set equal to 0
</span><span>
</span><span>y' = -2b + 88 = 0
</span><span>
</span><span>2b = 88
</span>
<span>b = 44 </span></span>
<span><span>a=44</span></span>
<span><span> both numbers are 44</span></span>
Answer:
P = 7.14%
The percentage of those 30 years or older that own an ipod is 7.14%
Step-by-step explanation:
Given;
Percentage of ipod owners Pi = 20%
Percentage who don't own ipod Pd = 100-20 = 80%
For age 30 or older;
Percentage of ipod owners who belong to this group
Po = 20% of Pi
Percentage who don't have an ipod but belong to this group Pu = 100-35% = 65% of Pd
The percentage of those 30 years or older that own an ipod is;
P = Po/(Po+Pu) × 100%
Po = 20% of Pi = 20% of 20% = 0.2×20 =4%
Pu = 65% of Pd = 65% of 80% = 0.65×80% = 52%
Substituting the values;
P = 4/(4+52) × 100%
P = 7.14%