Radiation from a cesium 133 atom completes 9,192,631,770 cycles each second how long does it take for this radiation to complete 1.5 million cycles

The important thing to note is to observe their units like what you would do in the dimensional analysis approach. You manipulate the units by cancelling out like units that appear both on the numerator and denominator side. As a result, the final unit should be in units of time like seconds.

1.5*10⁶ cycles * 1 second/9,192,631,770 cycles = 1.6317*10⁻⁴ seconds