The length of a rectangle is increased by 60%. By what per cent would the width have to be decreased to maintain the same area?

Let length of a rectangle = 100 m,
Breadth = 100 m
New length = 160 m,
New breadth = B meters
Then, 160 x B = 100 x 100
⇒ B = (100 x 100) / 160 = 125/2
Decrease in breadth = (100 - 125/2)% = 37¹/₂%