Question

if the length and breadth of a rectangular plot are increased by 50% and 20% respectively, then how many times will its area be increased?

Answer 1

let the length (l)be 2cm
and breadth (b) be 5 cm

area =l×b
= 2cm × 5cm
= 10cm²

New l = 2cm +2cm×50/100
= 2cm + 1cm
= 3cm

b = 5cm + 5cm×20/100
= 5cm + 1cm
= 6cm

New area = 3cm × 6cm
= 18cm²

increase in area = (18cm² - 10cm²)/10cm² × 100
= 8/10×100
= 80%
no. of times the area will increase = 18/10= 1.8 times