If the length of a rectangle is halved and its breadth is tripled, what is the percentage change in its area?
Let original length = 100 and original breadth = 100
Then original area = 100 × 100 = 10000
Length of the rectangle is halved
=> New length = $\dfrac{\text{Original length}}{2}=\dfrac{100}{2}=50$
Breadth is tripled
=> New breadth= Original breadth × 3 = 100 × 3 = 300
New area = 50 × 300 = 15000
Increase in area = New Area - Original Area = 15000 - 10000= 5000
Percentage of Increase in area = $\dfrac{\text{Increase in Area}}{\text{Original Area}} \times 100$
$=\dfrac{5000}{10000} \times 100=50\% $