Question

The length of a rectangle is increased by $a=30\%$ and breadth is decreased by $b=25\%$ . The percentage change in the area of the rectangle is___

Answer 1

Answer = option b

Initial area $=l\times b$

Final area $=1.3l\times 0.75b$

$=0.975l\times b$

$\%$ change $=(1-0.975)\times 100=2.5\%$ decrease