Question

A number is increased by 30% and then decreases
30%. Find the net increase or decrease percentage​

Answer 1

$\huge\sf\red{Answer}$

30%=30/100=3/10

30% decreased of a number means if the number is 10 ,then it will be 7.

30% increase of a number means if the number is 10 then it will be 13.

Further 30% decreased of means if the number is 10 then it will be 7.

Then, 10×10×10=1000 will be 7×13×7=637.

So, out of 1000 total decrease (1000 - 637)=363

Then, out of 1000/10=100 total decrease 363/10=36.3

Finally, Net decreased percentage in the number is 36.3%

hope it helps you mate :)

Answer 2

Answer:

Let the number be x.

Now, Increasing the number by 30%

» x + 3x/10 = 13x/10

Now decreasing by 30%

» 13x/10 - 39x/100

= (130x - 39)/100

= 91x/100

Now net decrease = x - 91x/100 = 9x/100

In %,

9x/100 = xy/100

» y = 9%

Therefore net decrease is 9%.