Question

Perimeter of rectangular plot is 340m 1 meter border is going to build along the border at a rate of 10 per square meter total cost howmuch

Answer 1

Let the length and breadth of the rectangular plot be  

x

metre and  

y

metre respectively.

perimeter of the rectangular plot = 340 m

=>  2 ( x + y ) = 340 ⋯ ( 1 )

Area of the 1 metre broad boundary

= area of the outer rectangle - area of the inner rectangle

= ( x + 2 ) ( y + 2 ) − x y = x y + 2 x + 2 y + 4 − x y = 2 ( x + y ) + 4

= 340 + 4     [from (1)]

= 344 square metre

Required cost of gardening = 344 × 10 = Rs.3440