Please help with these few math questions!!?

Question

1) 175% of what number is 21?

2) 28 is 87 1/2% of what number?

3) What is 26% of 81?

4) 37% of 55?

5) Find the Percent of increase: original price $4..New price $4.50?

6) Find the Percent of Decrease: Temp at noon 24F..Temp now 8F?

7) Find the percent of decrease: Original price $27..New $18?

Answer 1

The hardest part of these percentage problems is turning the words into an equation to solve. The secrets are to turn percents into a number divided by 100. Turn "is" into =. Turn "of" into multiplication (*). Turn "what number" into n. Turn "what percent" into n / 100.

PROBLEM 1:

175% --> 175 / 100
"of" --> *
"what number" --> n
"is" --> =
"21" --> 21

(175/100) * n = 21
n = 21 * 100/175
n = 2100 / 175
n = 12

Answer: 12

PROBLEM 2:

28 --> 28
"is" --> =
"87½%" --> 87.5 / 100 --> 7/8
"of" --> *
"what number" --> n

28 = 7/8 * n
28 * 8/7 = n
32 = n

Answer: 32

PROBLEM 3:
"What" --> n
"is" --> =
"26%" --> 26/100
"of" --> *
"81" --> 81

n = 26/100 * 81
n = 21.06

Answer 21.06

PROBLEM 4:

37% --> 37 / 100
"of" --> *
55 --> 55

37 / 100 * 55 = 20.35

PROBLEM 5:

Percent increase: Find the amount of increase, divide it by the original (lower) value.

The increase is 50 cents. The original price was $4.

0.50 / 4 = 0.125

But multiply by 100 to get a percent ---> 12.5

Answer: 12.5% increase

PROBLEM 6:

Same thing but figure the amount of the difference and divide by the original (higher) amount.

Difference is 16 degrees. Originally it was 24.

16 / 24 = 2/3 = 0.666666....

But multiply by 100 to get a percent:

Answer: 66 2/3 %

PROBLEM 7:

Why don't you try this one on your own, same as #6.

Answer 2

1) 175% of what number is 21?
(175/100)x = 21

2) 28 is 87 1/2% of what number?
28 = (87.5/100)x

3) What is 26% of 81?
(26/100)*81 =

4) 37% of 55?
(37/100)*55 =

5) Find the Percent of increase: original price $4..New price $4.50?
((4.50 - 4.00)/4.00)(100/100) = **
6) Find the Percent of Decrease: Temp at noon 24F..Temp now 8F?
((24 - 8)/8)(100/100) = **

7) Find the percent of decrease: Original price $27..New $18?
((27 - 18)/18)(100/100) = **

Replace % with /100
**Replace /100 with %

Answer 3

1)
1.75x = 21
x = 21/1.75
x = 12

2)
28 = .875x
x = 28/.875
x = 32

3)
x = .26(81)
x = 21.06

4)
x = .37(55)
x = 20.35

5)
new price - original price = $4.50 - $4.00 = $0.50
% = ($0.50/$4.00) x 100
% = 12.75%

6)
temp at noon - temp now = 24F - 8F = 16F
% = (16F/24F) x 100
% = 66.67% or 66 2/3 %

7)
original price - new price = $27 - $18 = $9
% = ($9.00/$27.00) x 100
% = 33.33 % or 33 1/3 %

:D

Answer 4

1) 175% of what number is 21?
Let 175% of x be 21 ---------- whenever you see % with any nymber write that No./100 here 175 % = 175/100 and of means multiplicatio
so 175 x/100 = 21
= 175 x = 2100
x = 2100 / 175 = 12

Answer 5

I'ma help you out with the first one. You should be able to figure it out from there because I really don't want to do your homework.

1) 175% of what numger is 21?
175% = 1.75
1.75 x n = 21 (divide each side by 1.75)
n=12

Answer 6

1. 21/ 1.75 = 12

2. 28/.875= 32

3. 81 X .26 = 21.06

4. 55 X .37 = 20.35

5. 12.5% increase

6. 66.66% decrease

7. 33.33% decrease

Answer 7

and what is your contribution to your homework?