The appropriate equation is that of continuity (for constant density, the stipulation that mass cannot accumulate means that volumetric flow is constant)
Rate of liquid volume flow = v*A = constant v is velocity and A is area
v1A1 = v2A2 or v is proportional to 1/A
v2 = v1(A1/A2) plug in values (proportional problems like these, you can use any units for v and A as long as they are the same for a particular quantity)
Please consider a tutor. Take care.