Question

in a class, three are 40 boys and their age is 16 years. one boy, aged 17 years, leaving the class and another joining, the average age becomes 15.875 years. the age of new boy is : ​

Answer 1

let age of the new boy be x.

there were 39 students whose age is 16years.

then

=>{(39×16)+x}÷40=15.875

=>(624+x)÷40=15.875

=>624+x=15.875×40

=>x=635-624

=>x=11

•

The age of the new big is 11 yrs

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