Question

If the length of a given rectangle is increased by 20% and the breadth is decreased by 20%. then the
resulting area is
a) Remains the same b) Increases by 5% c) Decreases by 4% d) Decreases by 5

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Answer 1

Answer:

let length be 100x

and breadth be 100y

area=100x × 100y=10000xy

new length=120x

new breadth =80y

new area=120x × 80y=9600xy

decrease=10000xy-9600xy=400xy

decrease%=400xy/10000xy×100

=40000xy/10000xy=4%

answer is decrease by 4%

Answer 2

Answer:

resulting area is decrease by 4%