A company increased its workforce by 35% for a busy phase, and later cut the enlarged workforce by 35%. What is the net change in the size of the workforce?

Take the original workforce as 100. After the rise it is 135, and after the cut it is $135\times 0.65=87.75$, so the net change is 87.75 - 100 = -12.25, a fall of 12.25%. 'No change' is the standard trap - the 35% cut is taken on the LARGER figure, so it removes more than the rise put in. The shortcut is $x$ squared$/100=35\times 35/100=12.25$, and the result is always a fall. The other two flip the sign or quote the raw 35%.