Question

A duster is of dimension $5x5x7$ all in cms, is sinked into a cylindrical vessel of radius $5$ cm and height $10$ cm. After insertion the level of the water is increased by $2.14$cm. Then by what percentage the part of the duster is above the layer ?

Answer 1

Dimension of the duster is $5\times 5\times 7{cm}^3$

Volume of the duster below the water layer

$=$volume of water increased

$=\pi r^{2}h$

$=3.14\times 25\times 2.14=167.99{cm}^3$

Total volume of the duster $=5\times 5\times 7=175{cm}^3$

Percentage of the duster part below the layer$=\frac{167.99}{175}\times 100=95.99\%$

Percentage of the duster part above the layer $100-95.99=4.01\%$

or $4\%$