The length of a rectangular field is thrice its breadth and its perime

1.	The length of a rectangular field is thrice its breadth and its perimeter is 240 m. The length of the field is(a) 80 m (b) 120 m (c) 90 m (d) none of these
Answer» (c) 90 m Because, Let us assume the Breadth of the rectangular field be x m. Let us assume the length of the rectangular field is thrice its breadth be 3x m Then, Perimeter of the rectangular field = 2(l + b) = 240 = 2(x + 3x) = 240 = 2(4x) = 240 = 8x = x = 240/8 = x = 30 ∴The length of the rectangular field is 3x = 3 × 30 = 90 m

The length of a rectangular field is thrice its breadth and its perimeter is 240 m. The length of the field is(a) 80 m (b) 120 m (c) 90 m (d) none of these

Answer»

(c) 90 m

Because,

Let us assume the Breadth of the rectangular field be x m.

Let us assume the length of the rectangular field is thrice its breadth be 3x m

Then,

Perimeter of the rectangular field = 2(l + b)

= 240 = 2(x + 3x)

= 240 = 2(4x)

= 240 = 8x

= x = 240/8

= x = 30

∴The length of the rectangular field is 3x = 3 × 30 = 90 m