Spherical Marbles of diameter $1.4 \mathrm{cm}$ are dropped into a cylindrical beaker of diameter $7 \mathrm{cm}$, which contains some water. Find the number of marbles that should be dropped in to the beaker, so that water level rises by $5.6 \mathrm{cm}$. 

The radius of the base of a cylinder is $14 \mathrm{cm}$ and its curved surface area is $880 {\mathrm{cm}}^2$. Its volume (in ${\mathrm{cm}}^3$) is______.

(Take $\pi =\frac{22}{7}$)

The lateral surface area of a cylinder is $352 {\mathrm{cm}}^2$. If its height is $7 \mathrm{cm}$, then its volume (in ${\mathrm{cm}}^3$) is:

(Take $\pi =\frac{22}{7}$)