RegionPlot3D[(x - 45/2)^2 + y^2 + z^2 >= 25/
4 && (x - 15)^2 + y^2 + z^2 >= 25 && (x - 35/2)^2 + y^2 + z^2 <=
225/4, {x, -5, 35}, {y, -15, 15}, {z, -15, 15}, PlotPoints -> 50,
PlotRange -> All]
The image output by this code is of very poor quality. How can I improve it.

contourRegionPlot3D[]from this answer, you'll get a better picture. – J. M.'s missing motivation Jan 25 '20 at 12:54