hey user!!
your answer is here...
given the ratio between the Length and breadth (width) of the rectangle is 5 : 3
let the Length and breadth of the rectangle be 5x and 3x approximately.
area of the rectangle = 240in²
therefore l × b = 240in²
==> 5x × 3x = 240in²
==> 15x² = 240in²
==> x² = 240/15
==> x² = 16
==> x = √16
==> x = 4in
hence, length of the rectangle = 5x = 5 × 4 = 20in
breadth of the rectangle = 3x = 3 × 4 = 12in
cheers!!