If the length of a rectangle is increased by 37\(\frac{1}{2}\)% and its breath is decreased by 20%, then find the percentage of change in its area.

10% 15% 20% 25%

10%

+37.5% = \(\frac{11}{8}\) -20% = \(\frac{4}{5}\)   change in length =   8--------11 change in width=     5---------4                     ————————————— Total effect:            10--------11 change in area = \(\frac{1}{10}\) × 100 = 10% increase