Average of 25 results is 20 . average of first 12 results is 15 and that of last 12 results is 18 .

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The average of $25$ results is $20 .$ the average of first $12$ results is $15$ and that of the last $12$ results is $18 .$ Then, the $13^{ th}$ results is

A

$100$

B

$101$

C

$104$

D

$103$

Solution

$\frac{12 \times 15+x+12 \times 18}{25}=20$

$x=500-[180+216]$

$x=500-396$

$x=104$

Standard 13

Quantitative Aptitude

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