You increase the size of a computer screen display by 20%. Then you decrease it by 20%. What is the size of the computer screen display now?

Question

asked Jul 7, 2017 172k views

2 Answers

Channing Huang · Answer 1 · 2017-07-12T22:14:52+0000

Answer: The size of computer display after 20 % increase and then 20 % decrease= 96 % of the original size.

Explanation:

Let the original size of computer be 100x , then if it increases by 20 %

then the new size of the computer=100x +20% of 100x

$=100x+(20)/(100)*100x\\=100x+20x\\=120x$

The size of computer after 20% increase= 120x

If size of computer is decreased by 20 % then

The new size of computer= 120x - 20% of 120 x

$=120x-(20)/(100)*120x\\=120x-24x\\=96x$

On comparing it to the original size , we get

$(96x)/(100x)*100=96\%$

Thus, the size of computer display after 20 % increase and then 20 % decrease= 96 % of the original size.