- Home
- Standard 13
- Quantitative Aptitude
4.Average
medium
Of the three numbers, the first is twice the second and the second is thrice the third. If the average of the three numbers is $10,$ the numbers are
A
$18,3,9$
B
$9,3,18$
C
$3,9,18$
D
$18,9,3$
Solution
Let, the numbers be $2 x, x$ and $\frac{1}{3}$
Then, average $=\frac{2 x+x+\frac{x}{3}}{3}=10 \Rightarrow \frac{9 x+x}{3 \times 3}=10$
or, $\frac{10 x}{9}=10,$ or, $x=9$
Hence, the numbers are $18,\,9$ and $3 .$
Standard 13
Quantitative Aptitude