The length of the rectangle is 12 dm and the width is 12 dm. By what percentage the area of the rectangle

The length of the rectangle is 12 dm and the width is 12 dm. By what percentage the area of the rectangle will decrease if its length is increased by 30%, and its width is reduced by 50%.

It is known that the length and width of a certain rectangle is 12 dm.

Let’s calculate what the area of this rectangle is equal to:

S = a * b.

S = 12 * 12 = 144 dm².

Increase the length of the rectangle by 30%:

a = 12 + (12 * 30%) = 12 + 12 * 0.3 = 12 + 3.6 = 15.6 dm.

Reduce the width of the rectangle by 50%:

12 * 0.5 = 6 dm.

Let’s calculate the area of the new rectangle:

S = 15.6 * 6 = 93.6 dm².

Let’s calculate by what percentage its area has decreased:

100 – (93.6 / (144/100)) = 100 – 93.6 / 1.44 = 100 – 65 = 35%.