Question

If the length of rectangle is increased by 10% and the area is un changed then its corresponding breadth must be decreased by

Answer 1

Let the length and width be a and b respectively

Area = ab

New Length = a + 10a/100 = 11a/10

Now,

New area = ab

=> 11a/10 × New width = ab

=> New Width = 10b/11

Decrease in width = b - 10b/11

Decrease in width = b/ 11

Percentage of Decrease = ( 10b /11)× 100 /b %

= 100/ 11

= 9.09 %

Answer 2

Let the length and width be a and b respectively

Area = ab

New Length = a + 10a/100 = 11a/10

Now,

New area = ab

=> 11a/10 × New width = ab

=> New Width = 10b/11

Decrease in width = b - 10b/11

Decrease in width = b/ 11

Percentage of Decrease = ( 10b /11)× 100 /b %

= 100/ 11

= 9.09 %