From the information given we know that the height of the cylinder is 3 in, and the volume of the cylinder is 10 in. cubed (assuming that the glass was full). We can substitute these values in the formula for volume.
Volume for Cylinder = Bh
10=pi x radius squared x 3
10/3 = 22/7 x radius squared
(10/3) x (7/22) = radiux squared
(5/3) x (7/11) = radius squared
35/33 = radius squared
[tex]35 \sqrt{33}/33 [/tex] = radius