Problem of the day for Monday, December 19

Friday's problem

December 15 hints and answers

Two opposite sides of a square are increased by 25 % while the other two are decreased by 40 %. Find the percent of decrease in the area of the square.


It's important to draw a diagram of the situation here, so you can understand what is going on.

Another useful strategy would be to choose a specific square to start with, rather than trying to do the general case right at first.

As always, be sure to explain the work you did to arrive at your answers!