Percent Word Problems

Question 1

what does “percent” mean?

Answer 1

divide by 100 (ex. 500% means 500/100 or 5)

Question 2

how do you express a decimal as a percent?

Answer 2

multiply by 100 and attach % sign

Question 3

how do you express a fraction as a percent?

Answer 3

multiply by 100 and attach % sign

Question 4

how do you go from percent to decimal?

Answer 4

drop % sign and divide by 100

Question 5

what are the two methods that can be used to find the percent of an unknown amount?

Answer 5

1) represent the unknown amount by x
2) assume the unknown amount is 100 items

Question 6

what does “percent of” mean?

Answer 6

it indicates you will be multiplying a given percent by a given number (ex: 40 percent of 100 is (40/100)*100 = 40

Question 7

various “percent of” translations:

Answer 7

1/10 percent of x -> (1/10)/100 = 1/1000 ->x/1000
700 percent of x -> 700/100 -> 7x

Question 8

what are examples of “what percent” problems

Answer 8

1: 100 is what percent of 50

Question 9

how do you attack a “what percent” problem?

Answer 9

let “what percent” be represented by x/100

Question 10

how would you set up the equation to solve “105 is what percent of 15?”

Answer 10

105 = (x/100)*15

Question 11

what is the formula for “percent less than” problems?

Answer 11

final value = (initial value)*(1 - (“percent less than”/100)), where “percent less than” is the percentage amount that it is reduced - so if we are told the value is reduced 20% the last part would be 1 - 20/100

Question 12

“percent less than” to “percent of” translations

Answer 12

Question 13

what is the formula for “percent greater than” problems?

Answer 13

final value = (initial value)*(1 -+(“percent greater than”/100)), where “percent greater than” is the percentage amount that it is increased

Question 14

in percent greater than problems, x% greater than y is equivelant to?

Answer 14

(100+x)%*y

Question 15

“percent greater than” to “percent of” translations

Answer 15

Question 16

if we increase something by 100% what does that do to the size of it?

Answer 16

doubles it, increases by 2 times - > 100 % greater than z = (1+100/100)z = (200/100)z - >translates to 200% of z

Question 17

“percent greater than” or markups, and “percent less than” mark down with variables are the same, you just use a variable instead of the actual % - true or false?

Answer 17

true

Question 18

how do you handle successive percent changes?

Answer 18

multiply the successive changes
ex: in attached photo

Question 19

what does “percent change” of a value indicate

Answer 19

the size of the increase or decrease of a value after a change in that value has occurred

Question 20

percent increase is simply a…

Answer 20

percent change of a value that has gone up

Question 21

percent decrease is a

Answer 21

percent change in a value in that has gone down

Question 22

what is the formula for percent change?

Answer 22

% change = ((final value - initial value)/initial value) * 100

Question 23

what other formulas can you use to calculate % change?

Answer 23

the percent greater than and percent less than formulas

Question 24

if you discount a $100 dress by 20%, it then costs $80. Will marking up the discounted dress by 20% get you back to the original price of $100?

Answer 24

no, since 20% of the smaller number 80 is not 20, its 16, so increasing the cost of the dress by 20% yields a price of $96

Question 25

what is percent profit?

Answer 25

when we express profit as a percentage of cost. So % profit = (profit/cost)*100

Question 26

can percent profit be negative?

Answer 26

yes, if costs exceed revenue your % profit will be negative since it will be % profit = (-profit/cost)*100

Question 27

how do you find the fractional change of something?

Answer 27

use the percent change formula without the multiplication by 100 at the end. ex: what is the fractional change in the price of a house that went from 250k to 450k dollars? -> (450-250)/250=150/250=3/5

Question 28

n is what percent of x (in addition to being formulated as n=(p/100)*x) could be expressed as?

Answer 28

n/x, since if n=2, and x=3 it would read, 2 is what percent of 3, and that is .66 from which you can get 66%