total electric flux

A point charge q1 = 3.05nC is located on the x-axis at x = 1.95m , and a second point charge q2= -6.45nC is on the y-axis at y = 1.05m .

Part A :-

What is the total electric flux due to these two point charges through a spherical surface centered at the origin and with radius r1 = 0.760m ?

Part B :-

What is the total electric flux due to these two point charges through a spherical surface centered at the origin and with radius r2 = 1.50m ?

Part C :-

What is the total electric flux due to these two point charges through a spherical surface centered at the origin and with radius r3 = 2.60m ?