Question

The length of a rectangle 8 cm more than the breadth. If the perimeter of the rectangle is 80 cm,
then the length of the rectangle is
(a) 16 cm (b) 24 cm (c) 28 cm (d) 18 cm

Answer 1

Let l and b be the length and breadth of the rectangle, then l = b + 8.
Perimeter of rectangle = 2 (l + b)
= 2(l + l − 8)
= 4l − 16
$$\begin{gathered} \Rightarrow 80=4l-16 \\ \Rightarrow 4l=80+16=96 \\ \Rightarrow l=24\mathrm{cm} \end{gathered}$$
Hence, the correct option is (b).