Question

For the next RSM Award ceremony, it was decided to decrease the length of the main poster by 12% and to increase its width by 15%. By how many percent did the poster's area change? Did it increase or decrease?

Answer 1

An increace of 1.2%

Explanation:

hope this is right

Answer 2

The Area of the poster has changed by +1.2%

The area has increased

Explanation:

Lets take the initial length of the poster as
`x`, and

Initial width of the poster as
`y`.

Therefore,

Initial area of the poster =
`xy`

Now after the changes to length and with:

length of the poster =
`x-(12)/(100) x`

=
`(88)/(100) x`

width of the poster =
`y+(15)/(100) y`

=
`(115)/(100) y`

New Area of the poster =
`(88)/(100) x*(115)/(100) y`

=
`(88*115)/(100*100) *xy`

=
`(10,120)/(10,000) *xy`

=
`1.012*xy`

Change in Area = Area after change - Initial Area

=
`1.012*xy-xy`

=
`0.012*xy`

Percentage area change = [Change in Area / Initial Area]*100

=
`(0.012xy)/(xy) *100`

=
`1.2`%

The area has increased