Question

the average of three numbers is 6 if two of numbers are 6 and 7 the third number is​

Answer 1

Answer:

5

Step-by-step explanation:

Given :

The average of three numbers is 6, The two of the numbers are 6 and 7.

To Find :

The third number.

Solution :

Let the third number be x,

We know that,

Average observation = $\frac{Sum\:of\:all\:observation}{Total\:number\:of\:observations}$

∴ Average observation = $\frac{6 + 7 +x}{3} = 6$

⇒ $\frac{13 + x}{3} = 6$

13 + x = 6 × 3

13 + x = 18

x = 18 - 13 = 5

∴ The third number is 5.

Answer 2

$\textbf{\underline{\underline{Answer :-}}}$

The Third number is 5.

$\textbf{\underline{\underline{Explanation :- }}}$

Given :

Total numbers = 3

The two numbers = 6 and 7

The Average of the data = 6

To find :

The Third number

Solution :

Consider the third number as x

✮ As we know :-

${\boxed{\sf{Average= \frac{Sum\: of\:observations}{Total\: observations}}}}$

$\sf{\implies} \: 6 =\dfrac{6 + 7 + x}{3}$

$\sf{\implies} \: 6 =\dfrac{13 + x}{3}$

$\sf{\implies} \: 6 \times 3 = 13 + x$

$\sf{\implies} \: 18 = 13 + x$

$\sf{\implies} \: x = 18 - 13$

$\sf{\implies} \: x = 5$

$\boxed{\sf{x = 5}}$

$\therefore$ The Third number is 5.

$\textbf{\underline{\underline{Verification :- }}}$

$\sf{\implies} \:\dfrac{5 + 6 + 7}{3} = 6$

$\sf{\implies} \:\dfrac{18}{3}=6$

$\sf{\implies} \: 6 = 6$

$\therefore$ The Third number is 5.