Question

The cost of fencing a rectangular plot of land is 1400 at the rate of 10 per metre.if the length of the land is 40 calculate bradth

Answer 1

$perimeter \: of \: rectangle \: = 2(l + b) \\total \: cost \div cost \: per \: meter = perimeter \\ \frac{1400}{10 } = 2(40 + b) \\ \\ b = 30$