A and B are two interlocking cogwheels having p teeth and q teeth respectively. One tooth on B is painted red. Find the values of p and q for which the red tooth on B contacts every gap on the cogwheel A as the wheels rotate.
Age 11 to 14 Challenge Level:
Keep a record of your results.
Try to find out what is special about the step sizes when you don't hit all the points.
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