Answer:
D
Step-by-step explanation:
Rate of interest is 6 %
<em><u>Solution:</u></em>
Given in question that,
simple interest = $ 3240
number of years = 9 years
principal sum = $ 6000
To find: interest rate
<em><u>The simple interest is given as:</u></em>

Where, "p" is the principal
"r" is the rate of interest
"n" is the number of years
<em><u>Substituting the values in above formula,</u></em>

Thus rate of interest is 6 %
Call the price of the bike before mark up 'x', then we have:
x + 0.25x = 210
1.25x = 210
x = 168
Therefore, the bike cost $168 before 25% price increase.
Answer:
$27.59
Step-by-step explanation:
You multiply 30 dollars by 0.85 (1-0.15, with the 0.15 being for the 15 percent off). Which gets you to $25.50, and you then multiply it by 1.082 (the 1.082 being the tax, and the .082 part equating to the 8.2% tax percentage).