Question

A cistern of capacity $8000$ litres measures extemally $3.3m$ by $2.6m$ by $1.1m$ and its walls are $5cm$ thick The thickness of the bottom is

• A. $1m$
• B. $1.1m$
• C. $1dm$
• D. $90cm$

Answer 1

Answer: (C)

$1dm$

Dimension of cistern:$l=3.3m=330cm$

$b=2.6m=260cm$

$h=1.1m=110cm$

Let thickness of bottom be ${}^{\prime }{x}^{\prime }cm$

Now $(330-10)(260-10)(110-x)=8000\times 1000$

$\Rightarrow 320\times 250\times (110-x)=8000\times 1000$

$\Rightarrow (110-x)=\frac{8000\times 1000}{320\times 250}=100$

$\Rightarrow x=10cm=1dm$