Correct Answer - Option 4 : 28%
Given:
20% decrease in length and 10% decrease in breadth
Formula used:
Area of rectangle = Length × Breadth
Calculation:
Initial area = L× B
Decreaseby length by 20% = (100-20)% L
New length = .80 × L
New breadth after decrease = (100-10)%B
New breadth = .90 × B
New area = 0.72 × LB
Difference in area = L× B - 0.72 × LB= .28×LB
Percentage change = (.28LB/LB) × 100 = 28%
∴ The percentage change in area is 28%