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

Answer:

+1.2%

Step-by-step explanation:

try it

Answer 2

Answer:

The Area of the poster has changed by +1.2%

The area has increased

Step-by-step 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 = $x-\frac{12}{100} x$

                                  = $\frac{88}{100} x$

width of the poster   = $y+\frac{15}{100} y$

                                  = $\frac{115}{100} y$

New Area of the poster = $\frac{88}{100} x*\frac{115}{100} y$

=$\frac{88*115}{100*100} *xy$

=$\frac{10,120}{10,000} *xy$

=$1.012*xy$

Change in Area = Area after change - Initial Area

=$1.012*xy-xy$

=$0.012*xy$

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

=$\frac{0.012xy}{xy} *100$

=$1.2$%

The area has increased