Question:
A field is 200 m long and 150 m broad. There is a plot, 50 m long and 40 m broad, near the field. The plot is dug 7m deep and the earth taken out is spread evenly on the field. By how many meters is the level of the field raised? Give the answer to the second place of decimal.
Solution:
Volume of the earth dug out $=50 * 40 * 7=14000 \mathrm{~m}^{3}$
Let 'h' be the rise in the height of the field
Therefore, volume of the field (cuboidal) = Volume of the earth dug out
⇒ 200 ∗ 150 ∗ h = 14000
$\Rightarrow \mathrm{h}=\frac{14000}{200 * 150}=0.47 \mathrm{~m}$