the mean age of a class is 16 years of the classteacher aged 40 years old is also included the mean age increases to 17 years the number of students in the class are...
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Answer:
Number of students in the class is 23.
Step-by-step explanation:
Let the total number of students in the class be "a" .
It is given in the question that the mean age of class of a students is 16 years.
So,
= > 16 years = ( sum of ages of students in the class in years ) / a
= > 16 a = sum of ages of students ...( i )
When the class teacher of age of 40 years, the mean age increases to 17 years.
Therefore,
= > 17 = ( sum of ages of students + 40 ) / ( a + 1 )
= > 17( a + 1 ) = ( 16a + 40 )
= > 17a + 17 = 16a + 40
= > 17a - 16a = 40 - 17
= > a = 23
Therefore the number of students in the class is 23.
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