Price of Mobile Phone

Project ID: 
3000000031
Question: 

The price of a mobile phone increased by $50\%$ then decreased by $50\%$.

Gregg says the price of the mobile phone is now the same as the original price.

Is Gregg's answer correct? If not, determine the correct result.

Answer 1: 

It is not correct. The new price is $75\%$ of the original price.

Answer 2: 

Gregg's answer is correct. The percent change of the price is $50\%-50\%=0\%$.

Answer 3: 

It is not correct. The new price is $25\%$ of the original price.

Answer 4: 

It is not correct. The new price is $175\%$ of the original price.

Correct Answer: 
Answer 1
Hint: 
  1. Original price: $x$
  2. Price after $50\%$ increase $y:\ y=1.5x$
  3. Price after $50\%$ decrease $z:\ z=0.5y=0.5\cdot1.5x=0.75x$

The new price ($z$) is $75\%$ of the original price ($x$).