Question:The length of a rectangle is increased by `60%` and the width is decreased by `20%`. The area decreases by :
A `37 1/2%`
B `60%`
C `75%`
D None
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+ Answer
A
+ ExplanationLet length = l and breadth = b
Let the required decrease in breadth be x%.
Then,`160/100 l xx ((100 - x))/100 xx b`
`= lb => 160 (100 - x)`
`= 100 xx 100`
`or 100 - x`
`= 10000/160`
`= 125/2 => x`
`= (100 - 125/2)`
`= 37 1/2.`