If the price of a television set is increased by 25%, by what percentage should the new price be reduced to bring it back to the original level?

The new price must be cut by 20%.

To return to the original after a rise, reduction % = rise / (100 + rise) x 100.

Here rise = 25%.

Reduction = 25 / 125 x 100.

25 / 125 x 100 = 20%.

So the new price should be reduced by 20%.