Imension of the duster is assumed as 5x5x7 cm3
Volume of the duster below the water layer
= volume of water increased
= πxrxrxh = 3.14×52×2.14 ≈ 168 cm3
Total volume of the duster = 5×5×7 = 175 cm3
Percentage of the duster part below the layer = 168×100/175 = 96%
Percentage of the duster part above the layer = 4%