Really ask for advice! Photography homework, thank you!

It depends on the camera. From1120 to 1/480, the speed is increased by several steps, and the aperture is increased by several steps from F 16 (the value is reduced by one step), so as to ensure the constant exposure. Similarly, in order to keep the total exposure unchanged, when iso changes from 100 to 200, the exposure can be reduced by one step, that is, the aperture value can be reduced by one step (the actual aperture is increased by one step).