Three point charges are located on xyz-coordinates as follows: q, = 4.00 nC is on the x-axis at x = 2.00 m, q, = -6.00 nC is on the y-axis at y = -1.00 m and q; = -5.50 nC is on the z-axis at z = 1.25 m. Calculate the total electric flux due to these three point charges through a spherical surface centered at the origin with radius: (a) 0.500 m, (b) 1.50 m, and (c) 2.50 m