How many four-stroke cycles occur each second in a cylinder at 3000 rpm?

In a four-stroke engine, one complete cycle (intake, compression, power, exhaust) occurs every two revolutions of the crankshaft. At 3000 revolutions per minute (rpm), the engine completes 3000/2 = 1500 cycles per minute. To convert this to cycles per second, divide by 60, resulting in 1500/60 = 25 four-stroke cycles per second.