12.1 - Percents Flashcards
2.4%
24/1000
Move the decimal two places to the left.
0.024
In January, John received an allowance of x dollars and saved n percent of it. In February, he received an allowance of 1.5x dollars and saved m percent of it. Assuming John saved no mother money than those portions of his allowance, did John save more money in January or in February?
I. n = 10
II. m is 50 percent of n
In January, John received an allowance of x dollars and saved n percent of it. In February, he received an allowance of 1.5x dollars and saved m percent of it. Assuming John saved no mother money than those portions of his allowance, did John save more money in January or in February?
John Saved nx/100 dollars in January and 1.5xm/100 dollars in February.
I. n = 10
Not sufficient without n.
II. m is 50 percent of n
Sufficient, because m=50%n can be substituted into the equation for m.
A certain company earned $10,000,000 in 2006. In 2007, the company earned 250 percent more than it did in 2006, how much did the company earn in 2007?
A certain company earned $10,000,000 in 2006. In 2007, the company earned 250 percent more than it did in 2006, how much did the company earn in 2007?
Percent more than = percent greater than so it’s 350 instead of 250.
$10,000,000 * (350/100) = $35,000,000
“Percent of” translations
“What percent” = x/100
What is the “fractional change” ?
Use the percent change formula and don’t multiply by 100
A house that once sold for $250,000 is now selling for $400,000. What is the fractional change in the price of the house?
A house that once sold for $250,000 is now selling for $400,000. What is the fractional change in the price of the house?
Use the percent change formula without multiplication of 100.
new - old/old
400,000 - 250,000 / 250,000 = 3/5 change
What is the value of n?
I. x percent of y percent of z percent of n = 400
II. z = 40/xy
What is the value of n?
I. x percent of y percent of z percent of n = 400
(x/100 * y/100 *z/100)n = 400. Cannot determine value of n without xyz.
II. z = 40/xy
40=xyz. Cannot determine value of n without an equation that includes n.
Both I & II.
Sufficient. Substitute value of xyz into equation from one (divided by 1003).
If 70% of A is equal to 80% of B, then A is what fraction of B?
If 70% of A is equal to 80% of B, then A is what fraction of B?
This is the same as asking what is A in terms of B?
(70/100)A = (80/100)B
A = (80/100)B /(70/100)
Flip the fraction to multiply.
A = (80/100)*(100/70)*B
A=8/7/B
If a and b are positive and x percent greater than a is equal to z percent less than b, then when of the following, in terms of z and x, correctly expresses the ratio of a to b?
If a and b are positive and x percent greater than a is equal to z percent less than b, then when of the following, in terms of z and x, correctly expresses the ratio of a to b?
On Saturday at a certain restaurant, the number of food orders increased by 10 orders each hour after the restaurant opened at 9am. At 3 pm, the restaurant had 30 percent more orders than it had at 9am. How many food orders were placed at 5pm?
On Saturday at a certain restaurant, the number of food orders increased by 10 orders each hour after the restaurant opened at 9am. At 3 pm, the restaurant had 30 percent more orders than it had at 9am. How many food orders were placed at 5pm?
1.3x= x + 60
.3x = 60
x = 200
200 orders at 9am, + 10 orders an hour = 280 orders at 5 pm.
The price of an item was marked up 20 percent when it should have been marked down 10 percent. As a result, the item was priced $60 higher than it should have been. What was the original price of the item?
The price of an item was marked up 20 percent when it should have been marked down 10 percent. As a result, the item was priced $60 higher than it should have been. What was the original price of the item?
20 percent higher is 1 + 20/100 = 12/10p
10 percent lower is 1 -10/100 = 9/10p
Subtract the lower price from the higher price and set equal to the provided value of $60.
12/10p - 9/10p = 60
3/10p = 60
Instead of dividing by .3, just multiply both sides by 10.
3p = 600
p = 200
At a certain computer store, the price of a desktop computer that was selling for $500 was increased by N percent and the price of a laptop computer that was selling for $2,000 was decreased by N percent. Following these price changes, the price of the two items was equal. If the price of a $60 printer was marked down N percent, what was its final price?
At a certain computer store, the price of a desktop computer that was selling for $500 was increased by N percent and the price of a laptop computer that was selling for $2,000 was decreased by N percent. Following these price changes, the price of the two items was equal. If the price of a $60 printer was marked down N percent, what was its final price?
500(1 + n/100) = 2000(1-n/100)
Simplify by distribution first.
500 + 5n = 2000 - 20n
25n = 1500
n = 60
Apply the 60% discount to the printer.
60*.6 = $24 for the printer
