A hemispherical bowl of radius 30 cm is filled with water by using a cylindrical glass. If the water from the cylindrical glass is poured 72 times to fill the bowl completely and the height of the glass is 10 cm, then what is the base radius of the cylindrical glass?

5 cm

We know that,

Volume of the hemisphere = \(\frac{2}{3}\) πr³

Volume of the cylinder = πr²h

According to the question,

Volume of the hemispherical bowl = 72 × Volume of the cylindrical glass

\(\frac{2}{3}\) π30³ = 72 × π × r² × 10

\(\frac{2}{3}\) × 27000 = 72 × r² × 10

= 18000 = 72 × r²

= 25 = r²

r = 5 cm