Can anyone help me solve these percent (%) problems...ASAP?

Question

These three types of percent problems can be solved using the A= PB formula. Here is the needed info to assist in solving the problems:

Question: What is P percent of B?
Given: P and B
Percent Formula: Solve for A

Question: A is Ppercent of what?
Given: A and P
% formula: Solve for B

Question: A is what percent of B?
Given: A and B
% formula: Solve for P

39. 3 is 60% of what?
41. 24% of what # is 40.8?
43. 3 is what % of 15?
45. What % of 2.5 is 0.3?

If you could please explain how you got your answer it would help. I just do not understand how to do these kinds of problems. I want to be able to understand it and show the work. Thanks so much anyone who helps. Best response of course gets 10 points! =) Thanks again.

Answer 1

I think the easiest way to solve percentage questions (without having to remember the formulas) is to write down the both percentages (100% and whatever other% you have) and cross-multiply.

Let me show you what I mean by that:

39.) 3 is 60% of what?

The "what" we are looking for is 100%.
x = 100%
3 = 60%

Now cross multiply:

x = 100%
....X.... ------> the capital X here means cross-multiplication
3 = 60%

x · 60% = 3 · 100%
x = 3 · 100 / 60
x = 5

=> 3 is 60% of 5
_______________

41.) 24% of what # is 40.8?

x = 100%
40.8 = 24%

Cross-multiply and solve for x:
x · 24% = 40.8 · 100%
x = 40.8 · 100 / 24
x = 170

=> The number we are looking for is 170.
=> 40.8 is 24% of 170.
______________

43.) 3 is what % of 15?

3 = x%
15 = 100%

x · 15 = 3 · 100
x = 3 · 100 / 15
x = 20

=> 3 is 20% of 15.
______________


45.) What % of 2.5 is 0.3?

0.3 = x%
2.5 = 100%

x · 2.5 = 0.3 · 100
x = 0.3 · 100 / 2.5
x = 12

=> 0.3 is 12% of 2.5
____________

Hope this helps!

Answer 2

Tricky problem, simple answer.

Let's say A and B are amounts, and P is percent.

The standard formula (the only one you need to remember) is that P (in percent) = A/B x 100. You can derive all the other questions from this one.

You must arrange the formula so that the unknown is on the left, and the two knowns on the right. If P is the unknown you're in good shape with the above formula.

If the unknown is not P but A, then you multiply both sides of the standard formula by B and divide by 100, and rearrange so the A is now on the left =>
A = P x B / 100

If the unknown is not P or A but B, then you multiply both sides of the standard formula by P and divide by B, and rearrange so that B is on the left =>
B = A/P x 100.

Try it with a pencil and paper so you get it all worked out.

Here are the answers to your quiz:

Question 1: What is P percent of B (given A and B)?
A (= P percent of B) = P/100 x B

Question 2: A is P percent of what (given A and P)?
B (= what A is P percent of) = A/P x 100

Question 3: A is what percent of B (given A and B)?
P (= the percent that A is of B) = A/B x 100

So you see all three are from the same initial formula or from rearranging its terms so that the unknown is on the left.

Here are the numerical examples:

Q39: Formula = Question 2 above.
B = A/P x 100 = 3/60 x 100 = 5

Q41: Same formula as Q39
B = A/P x 100 = 40.8/24 x 100 = 170

Q43: Standard formula
P = A/B x 100 = 3/15 x 100 = 20%

Q45: Standard formula
P = A/B x 100 = 0.3/2.5 x 100 = 12%

Good luck with this!

Regards,

Answer 3

39. 3/x = 60/100; 60/3=20 100/20=5
41. 24/100*x=40.8; .24*x=40.8; 40.8/.24=x; x=170
43. 3/15 = x/100; 1/5 = x/100; 100/5 = 20%
45. x/100 = .3/2.5; .3/2.5*100=12%
Both sides of the formula are equal. Whatever you do to reduce one side of the formula, you do the same to the other.

Try inserting numbers.
if A = 100, then PB is 2*50, 4*25, 5*20, 10*10, and so on.
therfore 1/2 = 50%; 1/4 = 25%; 1/5 = 20%; 1/10 = 10%

Answer 4

Cant answer everything but percent or % means parts per hundred so 8 parts in 100 is 8%. For your last specific questions 39. 3 is 60% of what - 60% means 60 parts per hiundred so 100 parts would be 5. If you take 3 and multiply 3*100/60 you get 5. As for 41, 24% of what is 40.8. You want 40.8*100/24 which is 4080/24 or 170. 3/15 is 20% ie one fifth. The last is a bit of a trick as it is a recurring, not exact, result. 8.333333333333333 (recurring) %

Answer 5

A=PB
B=A/P
P=A/B

39. 3 is 60% of what?

.6 x B = 3
B = 3/.6
B = 5

41. 24% of what # is 40.8?

.24 x B = 40.8
B = 40.8/.24
B= 170

43. 3 is what % of 15?

P x 15 = 3
P = 3/15
P = .20 = 20%

45. What % of 2.5 is 0.3?

P x 2.5 = .3
P = .3/2.5 = .12 = 12%

Answer 6

39. 3 is 60% of what?
3 = .6x --> x = 3/.6 = 5

41. 24% of what # is 40.8?
.24x = 40.8 --> x = 40.8/.24 = 170

43. 3 is what % of 15?
3 = 15x --> x = 1/5 =.2 = 20%

45. What % of 2.5 is 0.3?
.3 = 2.5x --> x = .3/2.5 = .12 = 12%

Just remember the word of means multiply and the word what is x. So in problem 45b you can just say x*2.5 = .3

Answer 7

im not sure what ur asking for for the 1st three. do they give numbers? or is it suppose to end up like BP = A something like that.




heres the basic concepts: %/100 = is/of

39.

60/100 = 3/x (simplify it and cross multi ply)
6/10 = 3/x
30 = 6x
x = 5

41.

24/100 = 40.8/x (same thing)
40.8 *100 = 24 *x
170 = x

43.
x/100 = 3/15 (same thing simplify if u can then cross multiply and isolate x)
20% = x

45. x/100 = .3/2.5
x = 12%

Answer 8

A formula that I learned in High School helps to explain it...

( is / of ) = ( % / 100 )

So for the first question, you would plug the 3 into the "is" part and 60 into the "%" part which gives you 60/100 for the right side of the equation or 0.60. You can treat "of" like a variable and multiply both sides by "of", and do the same thing for the 0.60 to get "of" by itself. "of" = 3 / 0.60 = 5

41: % = 24, is = 40.8, find of
43: is = 3, of = 15, find %
45: of = 2.5, is = 0.3, find %

To double check yourself, compare "is" and "of". "Of" will always be greater than "is".

Answer 9

39. 3/.6 = 5
41. 40.8/.24 = 170
43. 3/15 = .20 = 20%
45. 0.3/2.5 = 0.12 = 12%

Answer 10

#39. IS 39.3 times 0.60 = 23.58
#41. IS 4080 divided by 0.24= 170 or 170.0
#43 Is 30 divied by 15= 2% (could be wrong) maybe 20%
#45 Is 2.5 times 0.3= .075= 7.5%
As for the letter question i not too sure but it could be
PxB=A
A%xP=A
B/A=P
Good Luck and i put some web sites on the sources check them out.