What will be the cost of gardening 1 m broad boundary around a rectangular plot having a perimeter of 340 m at the rate of Rs. 10 per square metre?

Correct option is B

Given:
· Perimeter of the rectangular plot = 340 m
· Width of the boundary to be gardened = 1 m
· Cost of gardening = Rs. 10 per square metre
Formula Used:
1. Area of the boundary = Perimeter × Width
2. Total cost of gardening = Area of the boundary × Cost per square metre
Solution:
Let the side of plot be a and b
perimeter of rectangular plot = 2 ( a +b)
As per the question = 2 ( a +b) = 340
a + b = 170……….(1)
area of plot= ab
length of garden = a+2 and breath of garden= b+2
area of garden = (a+2)(b+2)-ab
=ab+2a+2b+4-ab
=2a+2b+4
=2(a+b)+4
by putting value from equation (1)
=2(170)+4
=340+4
=344
The rate of gardening is 10 per square meter.
Therefore required cost = 344$$\times$$​10=3440