Melody: Ok, I agree, this is a good question.
I assume that you mean the price falls by 40% of the NEW price.
Let the bike's original price by $100
It goes up by 20% which is $20. so the new price is $120.
Now the price goes down by 40%
40% of $120 is 0.40*120 = $48
New price is $120 - $48 = $72
So the original price was $100
Now it is $72
Price has dropped by $28
This is 28/100*100% decrease i.e. 28% decrease
You could choose any original price and the answer would be the same.
