CTET 2 Math and Science Sep 2016 Paper

Capacity of the tank which is in the form of cuboid
$=540{\mathit{m}}^3$
$\mathit{l}\mathit{b}\mathit{h}=540$
$\mathit{h}=\frac{540}{\mathit{l}\mathit{b}}$
$=\frac{540}{15\times 8}$
$=\frac{9}{2}$
Then, the height of the water tank is $\mathit{h}=\frac{9}{2}\mathit{m}$
Since, the water tank is $\frac{2}{3}$ full
Then, depth of the water $=\frac{2}{3}$ of $\frac{9}{2}=\frac{2}{3}\times \frac{9}{2}=3$
Hence, the required depth of water is 3m.