Question

If the mean of the numbers $27 + x$ , $31 + x$, $89 + x$, $107 + x , 156 + x$ is 82, then the mean of

$130 + x , 126 + x , 68 + x , 50 + x , 1 + x$ is

• A. 75
• B. 157
• C. 82
• D. 80

Answer 1

Answer: (A)

75

Answer 2

Given,

$82 = \frac { ( 27 + x ) + ( 31 + x ) + ( 89 + x ) + ( 107 + x ) + ( 156 + x ) } { 5 }$

⇒ $82 \times 5 = 410 + 5 x$ ⇒ $410 - 410 = 5 x$ ⇒ $x = 0$

∴Required mean is,

$\bar { x } = \frac { 130 + x + 126 + x + 68 + x + 50 + x + 1 + x } { 5 }$

$\bar { x } = \frac { 375 + 5 x } { 5 }$ $= \frac { 375 + 0 } { 5 }$ $= \frac { 375 } { 5 }$= 75.