Answer
352.5k+ views
Hint: In the class, children comprise both the girls and boys. If the percentage of girls are given then subtracting it from the number hundred we get the percentage of boys. Simply find the percentage of boys for the total children in the class.
Complete step-by-step answer:
Given that: In a class of $ 60 $ children, $ 30\% $ are girls
Class has both the girls and the boys.
Boys $ \% = 100\% - 30\% $
Simplify finding the difference of the terms in the above expression –
Boys $ \% = 70\% $
Now, the number of boys $ = 70\% $ of the total children
Here “of” suggests the multiplication operator.
the number of boys $ = 70\% \times 60 $
percentage is expressed as the number upon hundred. So, place $ 70\% = \dfrac{{70}}{{100}} $ in the above expression –
The number of boys $ = \dfrac{{70}}{{100}} \times 60 $
Find the factors for the above expression –
The number of boys $ = \dfrac{{7 \times 10 \times 6 \times 10}}{{10 \times 10}} $
Common factors from the numerator and the denominator cancel each other and therefore remove from the numerator and the denominator of the above expression.
The number of boys $ = 7 \times 6 $
Simplify finding the product of the terms in the above expression –
The number of boys $ = 42 $ Boys
Hence, there are $ 42 $ boys in a class.
So, the correct answer is “42”.
Note: The above example can be used by finding the percentage given of girls in number of girls and then have to subtract the number of girls from the total number of children to get the number of boys since the class contains boys and girls. Always convert the given percentage in the form of the fraction where the numerator is hundred.
Complete step-by-step answer:
Given that: In a class of $ 60 $ children, $ 30\% $ are girls
Class has both the girls and the boys.
Boys $ \% = 100\% - 30\% $
Simplify finding the difference of the terms in the above expression –
Boys $ \% = 70\% $
Now, the number of boys $ = 70\% $ of the total children
Here “of” suggests the multiplication operator.
the number of boys $ = 70\% \times 60 $
percentage is expressed as the number upon hundred. So, place $ 70\% = \dfrac{{70}}{{100}} $ in the above expression –
The number of boys $ = \dfrac{{70}}{{100}} \times 60 $
Find the factors for the above expression –
The number of boys $ = \dfrac{{7 \times 10 \times 6 \times 10}}{{10 \times 10}} $
Common factors from the numerator and the denominator cancel each other and therefore remove from the numerator and the denominator of the above expression.
The number of boys $ = 7 \times 6 $
Simplify finding the product of the terms in the above expression –
The number of boys $ = 42 $ Boys
Hence, there are $ 42 $ boys in a class.
So, the correct answer is “42”.
Note: The above example can be used by finding the percentage given of girls in number of girls and then have to subtract the number of girls from the total number of children to get the number of boys since the class contains boys and girls. Always convert the given percentage in the form of the fraction where the numerator is hundred.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Why Are Noble Gases NonReactive class 11 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let X and Y be the sets of all positive divisors of class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x and y be 2 real numbers which satisfy the equations class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x 4log 2sqrt 9k 1 + 7 and y dfrac132log 2sqrt5 class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Let x22ax+b20 and x22bx+a20 be two equations Then the class 11 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
At which age domestication of animals started A Neolithic class 11 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Which are the Top 10 Largest Countries of the World?
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Give 10 examples for herbs , shrubs , climbers , creepers
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference Between Plant Cell and Animal Cell
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Write a letter to the principal requesting him to grant class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Change the following sentences into negative and interrogative class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Fill in the blanks A 1 lakh ten thousand B 1 million class 9 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)