To start, we see that Ted works for 20 hours per week for 10 weeks.  This means he works a total of 200 hours over the summer.  He is paid $9 dollars each hour.  Therefore he makes $9 x 200 hours = $1800 total over the summer.  He then has to pay 10% in taxes, or .1 x $1800, leaving him with .  He buys the bike for $500, so he has $1620 - $500 = $1,120 to deposit at the bank.

Now we have to find out how much he will have 5 years later.  Since the bank pays 5% interest each year, we know that he will make 5% of what he has each year.  He starts with $1,120.  5% of this value is .  Adding this to the original $1,120 gives us $1,176.

This is also the same as multiplying instead by 1.05.  We repeat this step 5 times, giving us:

Use the simple interest formula:

Interest equals the initial amount multiplied by the annual interest rate multiplied by the number of years:

Let = interest owed

Let = principal (aka the initial amount of the loan)

Let  = interest rate

Let  = years passed

Therefore:

The question tells us that the price in January was x. To find the price in February, we decrease the price of x by 20%, which is the same as taking 80% of x. (In general, a P% decrease of a number is the same as (100 – P)% times that number). Continue to take 0.8 times the previous month's price to find the next month's price until we have the price for June, as follows:

January Price: x

February Price: 0.8 * January Price = 0.8x

March Price: 0.8 * February Price = 0.8 * 0.8x = 0.8² * x

April Price: 0.8 * March Price = 0.8 * 0.8 * 0.8x = 0.8³ * x

May Price: 0.8 * April Price = 0.8 * 0.8 * 0.8 * 0.8x = 0.8⁴ * x

June Price: 0.8 * May Price = 0.8 * 0.8 * 0.8 * 0.8 * 0.8x = 0.8⁵ * x; therefore, the price in June was 0.8⁵ ≈ 0.328 ≈ 0.33 times the original price.

Set up the following ratio

50/500 = n/100 

The cost of the tablet decreased by $50. The original cost is $500; therefore, 50 is the numerator and 500 is the denominator on the left side of the ratio.

Since a percentage is a part of a whole, n symbolizes the the percentage decrease.

To solve for n, you can cross multiply. So, 50(100) = n(500).

n = 10%

To find the cost on Tuesday, take 10% off Monday's price. In other words, find 90% of Monday's price. This is simply 0.9x. If we are to now add 10% of this value back onto itself to find Wednesday's price, we want 100% + 10%, or 110% of 0.9x.

1.1(0.9x) = 0.99x

This value is 1% smaller than x.

The price was lowered by $1,200 which is 40% of $3,000.

Let's call the original length and width of the rectangle  and , respectively.

The initial area, , of the rectangle is equal to the product of the length and the width. We can represent this with the following equation:

Next, let and represent the length and width, respectively, after they have been decreased.  The final area will be equal to , which will be equal to the product of the final length and width.

We are asked to find the change in the area, which essentially means we want to compare and . In order to do this, we will need to find an expression for in terms of  and . We can rewrite and in terms of and .

First, we are told that the length is decreased by fifteen percent. We can think of the full length as 100% of the length. If we take away fifteen percent, we are left with 100 – 15, or 85% of the length. In other words, the final length is 85% of the original length. We can represent 85% as a decimal by moving the decimal two places to the left.

= 85% of =

Similarly, if we decrease the width by 20%, we are only left with 80% of the width.

= 80% of =

We can now express the final area in terms of and by substituting the expressions we just found for the final length and width.

= ()() =

Lastly, let's apply the formula for percent of change, which will equal the change in the area divided by the original area. The change in the area is equal to the final area minus the original area.

percent change = (100%)

=(100%)

=(100%) = –0.32(100%) = –32%

The negative sign indicates that the rectangle's area decreased. The change in the area was a decrease of 32%.

The answer is 32.

The original reduction brings the total to  of the original value. Taking a  discount off that price gives  of the original value. This means the reduction had been .

The best way to answer this question is to plug in a number for n. Since you are working with percentages, it may be easiest to use 100 for n.

We know that in the month of February, the cost of this shirt was decreased by 10%. Because 10% of 100 is $10, the new cost of the shirt is $90.

In March, the cost of the shirt decreased another 10%. 10% of 90 is 9, so the cost of the shirt is now $81.

To find the total percentage decrease, you must divide 81 by 100 and subtract it from 1.

1 – (81/100) = 1 – 0.81 = 0.19

The total decrease was 19%.