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Half of the students in a class are 12 years old or less and one-sixth are 13 years old or more. The number of students that are between 12 and 13 years old is 5 more than the number of students that are 13 years old or more. How many students are between 12 and 13 years old?

 Apr 28, 2021

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Let  the total  number in the class  =  N

 

To find out  the  number  between 12 and 13 we  have

 

N - (1/2)N - (1/6)N  =    N  - (2/3)N   =  (1/3)N

 

And

 

(1/3)N  = (1/6)N  +  5

 

(1/3)N  - (1/6)N   =  5

 

(1/6)N  =  5

 

N = 5 ( 6)   = 30

 

(1/3) (30)   =  10  are between  12  and 13

 

 

cool cool cool

 Apr 28, 2021

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