Question

From 1994 to 1995 the sales of a book decreased by 80%. If the sales in 1996 for the same as in 1994, By what percent did the increase from 1995 to 1996?

Answer 1

400%

Explanation:

Let the sales be "100" in 1994

Since, it decreased 80%, the sales was:

80% = 80/100 = 0.8

0.8 * 100 = 80 (decreased by 80)

So, it was

Sales in 1995: 100 - 80 = 20

Sales in 1996 was same as in 1994, so that's 100

Thus,

Sales in 1994: 100

Sales in 1995: 20

Sales in 1996: 100

We need to find percentage increase form 1995 to 1996, that is what percentage increase is from 20 to 100?

We will use the formula:

`(New-Old)/(Old)*100`

Where

New is 100

Old is 20

SO, we have:

`(New-Old)/(Old)*100\\=(100-20)/(20)*100\\=4*100\\=400`

So, it increased by 400%