Question

the length rectangle is increased by 25% while breadth is diminished by 30% what is the impact of area.

Answer 1

Let the length of the rectangle = x

Increasing 25%

= x + 0.25 = 1.25x

Length = 1.25x

Let the breadth of the

rectangle = y

diminished by 30%

= y - 0.3y = 0.7y

breadth = 0.7y

Area of rectangle= length x breadth

= (1.25x) (0.7y)

= 0.875xy

Change in Area --

xy - 0.875xy = 0.125xy

Percentage of area changed-

= 0.125xy÷xy*100

= 12.5 % .

Answer is 12.5% .

Answer 2

Answer:

12.5 %    (decrease)

Step-by-step explanation:

Let the original length be 'l' and breadth be 'b'.

  ∴ Area = length * breadth

              = lb

When length increases by 25% and breadth is diminished(decreased) by 30%,

   length = l + 25% of l   = l + (25/100)l

              = l + 0.25l          = 1.25l

   breadth = b - 30% of b   = b - (30/100)b

                 = b - 0.3b       = 0.7b

∴ Area = (1.25l) * (0.7b)     = 0.875lb

       [As 0.875lb < lb,   area is decreased]

∴ Change % = (lb - 0.875lb) / lb * 100%

              = [ 0.125lb ] / lb * 100%

              = (0.125) * 100%

              = 12.5%