Respuesta :

The answer is 20%

If 50 is your 100%, take 100 and 90 for example it would be obvious that is it 10% off, so with 50 since it is half of 100 you double the 10% which will be 20%. :)

Answer:

-20% decrease

Step-by-step explanation:

40-50=-10

-10/50=-0.2

-0.2*100=-20%

Hope this helps.