Question

A number first increased by 15% then decreased by 15% find the net increase or decrease percent

Answer 1

Answer:

The number decreased by 2.25%.

Step-by-step explanation:

let the original number be x.

The value of x is increased by 15%.

The new number is,

$x[1+\frac{15}{100}]=1.15x$

Now this new number is decreased by 15%.

Now the new number is:

$1.15x[1-\frac{15}{100}]=1.15x\times0.85=0.9775x$

The difference between the original number and new number is,

Difference = New - Original

                  = 0.9775 x - x

                  = -0.0225 x

Thus, the number decreased by 2.25%.

Answer 2

Answer:

The number decreased by 2.25%.

let the original number be x.

The value of x is increased by 15%.

The new number is,

x[1+\frac{15}{100}]=1.15xx[1+

100

15

]=1.15x

Now this new number is decreased by 15%.

Now the new number is:

1.15x[1-\frac{15}{100}]=1.15x\times0.85=0.9775x1.15x[1−

100

15

]=1.15x×0.85=0.9775x

The difference between the original number and new number is,

Difference = New - Original

= 0.9775 x - x

= -0.0225 x

Thus, the number decreased by 2.25%.