2/3% of (?) =33 i know this seems like a simple question, but it has me stumped

Expert Answers
cburr eNotes educator| Certified Educator

The easiest way to solve this is to convert the 2/3 into a decimal.

2/3 = 0.66666 . . . .

You can round this to 0.67

To find a percentage of something, you multiply it by the percentage. The important thing to remember is that a percent is a 100th. So, to find 5 percent of something, you have to multiply by .05!! In this case, you will multiply by 0.0067.

The equation for this problem is:

Y x .0067 = 33

You want to isolate Y on one side of the equal sign. To do that, divide both sides by .0067.

Y = 33 / .0067

Y = 4925

CHECK:

4925 x .0067 = 33 ??

close enough -- it equals 32.9975, which would round to 33.

 

atwama | Student

Set out your question/problem as an equation

 2/3% of x = 33 ………… [Equation 1]

 Then follow these 4 simple steps.

1. Set x = the unknown (or what you term as the ? mark)

So your [Equation 1] becomes: 2/3x = 33 ….. [Equation 2]

 2. Convert 2/3 into %, expressed in decimals, so

 % = (2/3) x 100/1

     = 200/3

     = 66.66667% (rounded to about 66.7%)

 3. Divide 66.7 by 100 to get % expressed in decimals, so,

 % = 66.7/100

     =  0.667

 3. Substitute 0.667 for 2/3 into [Equation 2], and solve for the unknown, x, so

     2/3x = 33

  0.667x = 33

 Isolate x, so divide both sides of equation by 0.667, then

        x = 33/0.667

        x = 49.4752 (rounded off to 49.5)

 Therefore, your unknown (x) is 49.5

 4. Check your answer: Substitute x = 49.5 into either Equation 1 or 2, and check if right hand side (RHS) answer equals to Left Hand Side (LHS), so

             2/3x = 33, where x = 49.5

    2/3(49.5) = 33

 0.667(49.5) = 33

              33 = 33

          RHS = LHS

 Therefore, your answer x = 49.5 is correct!

givingiswinning | Student

2/3 =33/x

cross multiply: 

2x = 99

divide by 2

x = 49.5

atyourservice | Student

2/3% of (?) =33

all you need to do is set up a proportion:

When they say 2/3 of a number is 33, it means that 33 is a percentage of the x (unknown number), so you set it in a way that has the 33 on top:

`2/3 = 33/x`

cross multiply: (2 by x) and (33 by 3)

2x = 99

divide by 2

`(2x)/2 = 99/2`

x = 49.5

to check:

49.5 / 3 = 16.5

16.5 x 2 =33