Question

the length of a rectangle is decreased by 10% but the area remains the same then percentage increase in the breadth of rectangle is​

Answer 1

Let original length be 'l' and breadth be 'b'

Hence, Area, A = l*b .....................(1)

New length = 0.9*l

New breath be B

But Area is same, so,

A = 0.9*l*B ...................................(2)

By (1) and (2)

l*b = 0.9*l*B

b = 0.9B

Hence, B = b/0.9

Hence, inc. in breadth = (B - b)*100/b

                                 = (b/0.9 - b)*100/b

                                 = 0.1b*100/b

                                = 10 %