Question

the average age of three brothers is 15 year s .if the age of two brothers is 15 years and 12 year ,find the age of the third brothet

Answer 1

Now:

Average = Sum of all numbers / number of terms

Here average = 15

Number of brothers = 3

So:

15 = Sum / 3

==> Sum = 15 * 3

==> Sum = 45

Given:

the age of 2 brothers are 15 and 12.

Hence Sum = 15 + 12 + age of third brother

==> 45 = 27 + age of 3rd bro

==> age of third bro = 45 - 27

==. age of third bro = 18

The age of the third brother is 18

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