Question

The height of 2 men is 1.65m. When the third man joins, there average height becomes 1.6m. What is the height of the third man?

Answer 1

Given :-

Height of two men taken together = 1.65m

Let the height of the third man be = x

The average of their height = 1.6 m

$\color{olive}average = \color{hotpink} \frac{sum \: of \:all \: values }{count \: of \: values}$

Which means :-

The average of the heights of these 3 men :-

$\color{olive}= \frac{1.65 + x }{3} = \color{hotpink}1.6$

$= 1.65 + x = 1.6 \times 3$

$= 1.65 + x = 4.8$

$= x = 4.8 - 1.65$

$\color{olive}= x\color{hotpink} = 3.15$

Let us check whether or not we have found out the correct value of x, by placing 3.15 in the place of x :-

$= \frac{1.65 + 3.15}{3} = 1.6$

$= \frac{4.8}{3} = 1.6$

$= \texttt{1.6 = 1.6}$

$\texttt{\color{olive}LHS =\color{hotpink} RHS }$

As the left hand side of the equation is equivalent to the right hand side of the equation, we can conclude that we have found out the correct value of x.

Therefore , the height of the third man is :-

$\color{hotpink} \texttt {= 3.15 m}$