If 30% of R is equal to 75% of S, what is 50% of S if R=30?

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llltkl's profile pic

llltkl | College Teacher | (Level 3) Valedictorian

Posted on

30% of R is equal to 75% of S.

So, expressing the given percentage condition as a fraction of 100 we get:

`30/100*R=75/100*S`

Substituting `R=30` in the above relation we get:

`30/100*30=75/100*S`

`rArr 900=75*S`

`rArr S=900/75=12`

Hence, 50% of S=`50/100*12=6`

Therefore, the value of 50% of S is 6.

Sources:
malkaam's profile pic

malkaam | Student, Undergraduate | (Level 1) Valedictorian

Posted on

R = 30

30% of R = 75% of S

50% of S = ?

30% of R = 30 * 30% = 9

30% of R = 75% of S

9 = 75% of S

9 = 75/100 * x

9 = 0.75 * x

9/0.75 = x

12 = x

S = 12

50% of S = ?

50/100 * 12 = x

6 = x

50% of S = 6 Answer.

sid-sarfraz's profile pic

sid-sarfraz | Student, Graduate | (Level 2) Salutatorian

Posted on

QUESTION:-

If 30% of R is equal to 75% of S, what is 50% of S if R=30?

SOLUTION:-

According to question:-

30% of R = 75% of S

R = 30

50% of S = ?

Therefore;

30% of R = 75% of S

Insert the value of R;

30% of 30 = 75% of S

Changing percentage into fraction form:-

30/100 x 30 = 75/100 x S

`30/100*30=75/100*S` 

`0.3*30=0.75*S`

`9=0.75*S`

Divide both sides by 0.75 :-

`9/0.75=S`

`12=S`

`i.e, S=12`

Now as required in the question, we have to find;

50% of S=?

Therefore;

where S = 12.

Hence,

50% of S

= 50% of 12

= 50/100 x 12

= 0.50 x 12

= 6

Therefore the answer of this question is 6. Simple. 

acompanioninthetardis's profile pic

acompanioninthetardis | Student, Undergraduate | (Level 1) Valedictorian

Posted on

r=30

multiply by .3 to get 9

then 9*4/3 =s

(the recipricol of the .75% or 3/4 comming from s)

you get

s=12

then you get .50 of 12 which is 6

the ans. is 6

nisarg's profile pic

nisarg | Student, Grade 11 | (Level 1) Valedictorian

Posted on

If 30% of R is equal to 75% of S, what is 50% of S if R=30?

r=30 so 30% of r is 9

9=3/4 S

36=3s

S=12

and 50% of S is 6

taangerine's profile pic

taangerine | Student, Grade 12 | (Level 1) Valedictorian

Posted on

30% of R is equal to 75% of S, what is 50% of S if R=30?

Before doing the following problem, know: 

  • Percentages can be written as fractions or decimals. In this case, we will be using fractions. 30% will be 30/100, 75% will be 75/100, and 50% will be 50/100.
  • 'Of" stands for multiplication in math.
  • 'Is' stands for equal to in math

Now, let's rewrite the first part of the problem using what we know: `(30/100)R=(75/100)S`

Simplify and isolate S by cross multiplying. `S=30/75R or 2/5R`

Now, let's do the 2nd half(using what we have simplified already): `50/100S=2/5R`

And from the 2nd half, we know that R=30. `50/100S=2/5(30)` 

Simplify and your final answer should be `S=6`

ayl0124's profile pic

ayl0124 | Student, Grade 12 | (Level 1) Valedictorian

Posted on

Word problems can be overwhelming and confusing. To organize your thoughts, you should set up numerical equations. 

Since 30% of R is equal to 75% of S, then:

`"0.30R" = "0.75S"`

Solve for "S."

`"S" = ("0.30R")/"0.75"`

`"S" = "0.4R"`

Because you are given a value for "R," you can simply plug in the value and solve for "S" when "R" is 30.

`"S" = 0.4(30)`

`"S" = 12`

But since you are solving for 50% of "S," multiply 12 by 50% or 0.50.

`12 xx 0.50 = 6`

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