What you want to determine is how long it takes the fast spinning turntable to complete one more cycle than the slower pendulum. Given that the rate of the turntable is 36.25 RPM, the number of rotations it make in T minutes is 36.25T. Meanwhile the slower pendulum has completed only 36T complete swings. For the faster turntable to "lap" the slower pendulum it must complete one extra cycle in that time T. So:
36.25T = 36T + 1.
Solve for T, and from that the number of cycles of the pendulum.
