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- Quantitative Aptitude
4.Average
hard
Out of nine persons$, 8$ persons spent $Rs.\, 30$ each for their meals. The ninth one spent $Rs.\, 20$ more than the average expenditure of all the nine. The total money spent by all of them was (in $Rs.\,$)
A
$260$
B
$290$
C
$292.50$
D
$400.50$
Solution
Expenditure of $9^{th}$ person $=$ $Rs.\,x$
Now, according to the question,
$x-\frac{x+8 \times 30}{9}=20$
$\Rightarrow \frac{9 x-x-240}{9}=20$
$\Rightarrow \quad 8 x-240=180$
$\Rightarrow \quad 8 x=240+180=420$
$\Rightarrow x=\frac{420}{8}=52.5$
Total expenditure $=Rs.\,(52.5+240)=Rs.\, 292.5$
Standard 13
Quantitative Aptitude