$A$ right cylindrical vessel is full with water. How many right cones having the same diameter and height as those of the right cylinder will be needed to store that water?

Water flows into a tank with a base of $150\, m \times 100\, m$ through a pipe with a cross-section of $2\, dm \times 1.5\, dm$ at a speed of $15\, km/h$. In what time will the water reach a depth of $3\, m$? (in $hours$)

If the length,breadth and height of a rectangular parallelopiped are in the ratio $6:5:4$ and if the total surface area is $33,300\, m^{2}$,then the length,breadth and height of the parallelopiped (in $m$) respectively are:

The total surface area of a hemisphere is $41.58 \text{ cm}^2$. Find its curved surface area (in $\text{cm}^2$).

If the diameter of a sphere is decreased by $25 \%$,its curved surface area will be decreased by (in $\%$).

If the measured value of the radius is $1.5 \%$ larger,the percentage error (correct to one decimal place) made in calculating the volume of a sphere is