A regular pyramid has a square base. The height of the pyramid is 22 cm and side of its base is 14 cm. Volume of pyramid is equal to the volume of a sphere. What is the radius (in cm) of the sphere?
U, V and W together can make a chair in 20 minutes. U and V together can make it in 25 minutes. How much time will (in minutes) W alone take to make the chair?