help me with my 9th grade math...?

Just remember that n% is simply n/100

1) 18 is 20% of what number? Call number N

20%N = 18

(20/100) N = 18

N = (100/20) 18 = 5 * 18 = 90

18 is 20% of 90

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2) what is b% of 6? (explain it to me plzzz....)

b% 6 = (b/100)6 = 6b/100 = 0.06b

b% of 6 is 0.06 b

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3) m is 62(1/2)% of what number? Call number N

62(1/2)% N = m

(62.5/100) N = m

0.625N = m

N = (1/0.625)m = 1.6m

m is 62(1/2)% of 1.6 m

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4) how many 5ths there in 280%

Depends what you mean by 5th

1/5th of 280% is 56%

How many 56% are there in 280%? 5 of course, since 56% is 1/5 of 280%

If you mean a fifth of 100% = 20%

How many 20% are there in 280%? = 280% / 20% = 280/20 = 14

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5) what is 62(1/2) of 80?

Do you actually mean 62(1/2)% ???

62(1/2)% 80 = (62.5)/100 * 80 = (62.5 * 80) / 100 = 50

62(1/2)% of 80 is 50

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6 )c is 83(1/3) of what number? Call number N

Do you actually mean 83(1/3)% ???

83(1/3) = 83*3/3 + 1/3 = 249/3 + 1/3 = 250/3

83(1/3)% = (250/3)% = (250/3) / 100 = 250/300 = 5/6

83(1/3)% N = c

(5/6) N = c

N = (6/5)c = 1.2c

c is 83(1/3)% of 1.2 c

1) 20/100 of x = 18 so the number is 90

2) 1% is 1/100 of an amount so b x 1% = b/100 x 6 = 6b/100

3) m= 62.5/100 times the number so

The required number = 100m/ 62.5

4) 1/5 of 100 = 20% How many 20% in 280%

There are 14

5) Do you mean what percentage of 80 is 62.5

If so we have 62.5/80 x 100 = 78.125%

6) c is 250/3 divided by 100 of the required number

The required number = 300c/250 = 30/25 = 6/5 = 1 and 1/5

(I have assumed you meant what percentage)

1) 18 x 5 because 20% goes into 100% 5 times.

2) are you sure it isnt a 6? The b doest maker sense.

3) pass

4) 280 divided by 20 i think. Not sure.

5) Work out what 1% of 80 is an multiply it by 62.5

*if you meant 62.5 by 62(1/2) that is.

6) Pass!

Sorry that didn't help much. I'm in 8th grade haha that was useless xd

Ok, there are KEY WORDS that will help you set up better.

The word "OF" is the same thing as saying times or multiplying

The word "IS" is the same thing as saying equals or equal to.

As such, your first problem.. 18 is 20% of what number...

18 = 20% times X

for 3 and 6 if whats in perenthasese is the percent then its

124 and 279 respectively

I suggest you to better take a online math tutor etutorworld.net help through which you can solve your math problem in a less cost.