Answer:
You can increase by 100% and more of the price in something but you can never decrease more than 100% of something.
Explanation:
If you have something that costs 8 dollars to begin with then all of the sudden it costs 20 dollars, it increased by 150%. 8 is 100$ of 8, 4 is 50% of 8. 8+4=12. 12+8=20. The price began at 8 then increased by itself plus half of it which is 12.
IF you decrease the price by 150% it'll be -20 dollars. You cant physically have negative amount of money.