A hemispherical basin of $150$ cm diameter holds water one hundred and twenty times as much as a cylindrical tube. If the height of the tube is $15$ cm, then the diameter of the tube is:

A cylindrical box of radius $5$ cm contains $10$solid spherical balls each of radius $5$ cm. If the topmost ball touches the upper cover of the box, then volume of the empty space in the box is:

Water flows into a tank, $100$ m by $150$ m, through a rectangular pipe $1.5$ m$\times 1.25$ m at a speed of $20$ km/hr. In what time will the water rise by $2$ m?

A well with $28$ m inside diameter is dug $8$ m deep. The earth taken out of it has been evenly spread all around it in the shape of a circular ring of width $21$ m to form an embankment. Find the height of the embankment.