Question

a number is increased by 30% and then it is decreased by 15%. the net increase or decrease Percent is​

Answer 1

Step-by-step explanation:

There is net decrease of 9%.

Step-by-step explanation:

Since we have given that

A number is increased by 30%.

Then a number is decreased by 30%.

Let x = 30%

y = -30%

So, the net increase or decrease percent would be

\begin{gathered}x-y-\dfrac{xy}{100}\\\\=30-30-\dfrac{30\times 30}{100}\\\\=-\dfrac{900}{100}\\\\=-9\%\end{gathered}

x−y−

100

xy

=30−30−

100

30×30

=−

100

900

=−9%

Hence, there is net decrease of 9%.

# learn more:

A no. is increased by 20%. then it is dec by 20% calculate the net increase or decrease percent

Answer 2

Let the number be 100.

First, the number is increased by 30%.

Means,

=> 100 + (30% of 100)

= 100 + (30/100 × 100)

= 100 + 30

= 130

Then, the result is decreased by 15%.

=> 130 - (15/100 × 130)

= 130 - 19.5

= 110.5

Final number = 110.5

Original number = 100

Since final number > original number, there is a net increase.

% increase = Difference / Original number × 100

Difference = 110.5-100 = 10.5

% increase = 10.5/100 × 100 = 10.5% increase.