Quantitative Aptitude Ques 529
Question: A well 20 m in diameter is dug 14m deep and the earth taken out is spread all around it to a width of 5 m to form an embankment. The height of the embankment is
Options:
A) 10 m
B) 11 m
C) 11.2 m
D) 11.5 m
Show Answer
Answer:
Correct Answer: C
Solution:
- [c] Radius of the base of well $ =\frac{20}{2}=10,m $ Volume of the earth taken out $ =\pi r^{2}h=\frac{22}{7}\times 10^{2}\times 14 $ Let the height of embankment be x m. Here, $ R=15m, $ $ r=10m $ Then, volume $ =\pi (R^{2}-r^{2})\times x=\frac{22}{7}\times (15^{2}-10^{2})\times x $ $ =\frac{22}{7}\times 25\times 5\times x $ Clearly, $ \frac{22}{7}\times 25\times 5\times x=\frac{22}{7}\times 10^{2}\times 14 $
$ \Rightarrow $ $ x=\frac{100\times 14}{25\times 5}=11.2m $
BETA
