Two interconnected, circular gears travel at the same circumferential rate. If Gear A has a diameter of 80 centimeters and Gear B has a diameter of 50 centimeters, what is the ratio of the number of revolutions that Gear A makes per minute to the number of revolutions that Gear B makes per minute?  Choose one:
A) 8 : 5	B) 9 : 25	C) 5 : 8	D) 25 : 9	E) can not be determined from the information provided

Rationale: same circumferential rate means that a point on both the gears would take same time to come back to the same position again . hence in other words , time taken by the point to cover the circumference of gear a = time take by point to cover the circumference of gear b time a = 2 * pi * 25 / speed a time b = 2 * pi * 40 / speed b since the times are same , 50 pi / speed a = 80 pi / speed b speeda / speed b = 50 pi / 80 pi = 5 / 8 correct option : c
Answer: C