Help me a.s.a.p.! Math problems!?

Question

Can someone please describe to me how to do these problems... I have a test that's coming up.. I'm a new student starting college... I need help with these.. 15% of 30
20%of 100
11% of 25
Stuff like that,please describe! Thanks so much!

Answer 1

take the percent change it into a decimal. (ex. 15% - 0.15) and multiply it by the number
15% of 100
.15x100=15

Answer 2

Percents are really say "some number" per 100.
Example 15 girls in a class of 100 students is 15%
(15 per 100, or 15/100 or 0.15)

If the class were 200 and there were 15 girls then you must set up an equation like this : 15/200 = x/100 and solve it

to solve this equation, multiply both sides by 200 first
so 15 = 2x
now divide by 2, so 7.5 = x
The answer is 7.5%

ps. Write a letter to your local school board for not teaching you this before you got to college.

Answer 3

% just mean out of 100, so 20% is 20/100, 15% is 15/100 etc.
The word "of" means to multiply. So 15% of 30 is the same as 15%x30. And that really means 15/100x30=450/100=4.5.
So, 20% of 100=20/100x100=2000/100=20.
11% of 25=11/100x25=275/100=2.75.
The basic rule is multiply the percent times the whole number and moved the decimal two spots to the left.
Good luck.

Answer 4

The answers are a.) 20% of hundred is 20. B.) 11 of 25 is 2.75 C: 15% of 30 is 4.5. You can change the percentage into a fraction or straight multiplication and move over decimal point two places.

Answer 5

15 % of 30 is 15*30/100=4.5

20% of 100 = 20*100/100 =100

11% of 25 = 11*25/100 =3.75

Answer 6

Not to be offensive, but you registered for a college level course involving math when you can't remember grade 6 / grade 7 math?

Dealing with percentages: Divide % by 100, and multiply against value you want the percentage of. In case you've forgotten, you can move the decimal two to the left when dividing by 100 to obtain the answer.

Answer 7

When we take the percentage of a number it means we are displaying it as a fraction of hundred.
i.e. 10 % means 10/100
or 200% means 200/100
And consequently when we apply the percentage to another number we are just comparing two fractions.
e.g. saying 5% of 50 is like saying...if we have 5 out of 100...how much will we have out of 50. Its a problem of ratio.
So we can say 5/100 = x/50
and cross multiplying gives us 5*50/100 =x
and hence x = 2.5
so for any such problem e.g as you say 15% of 30 display both sides as a fraction and cross multiply.
15% = x/30
15/100 = x/30
x = 15*30/100
x = 4.5
so 15 % of 30 is 4.5
Hope this helps :)

Answer 8

you convert the percentages into decimals 15% = .15, 20%=,20, etc. then you just multiply!

.15 X 30 =4.5
.20 X 100 = 20
.11 X 25 = 2.75

Answer 9

just convert the percentage into a decimal and multiply.

So for example 15% of 30 would be 0.15 x 30 the answer is 4.5
same with 20% of 100. that would be 0.20 x 100 = 20

Answer 10

Use A as basis number
Use B as percentage (to convert your percentage number
for use in your formua: Enter whole number on your calculator
& then press % key.)
Mutiply A*B & you will obtain X (your unknown number)

Formula is (A*B)=X

Answers: : 15% of 30 >(30*.15) = 4.5
20% of 100 > (100*.20) = 20
11% of 25 > (25*.11) = 2.75

Answer 11

That doesn't look like college level mathematics, but nevertheless...

What is 1% of anything? It's 100th. So divide it by 100 to get 1%.

n% of something is n time 1% of something.
So n% of anything is (thing*n/100)
30 * 15 / 100 = 4.5
100 * 20 / 100 = 20
25 * 11 / 100 = 2.75