Question

a rectangular lawn 80M by 60 M has to roads each 10 M wide running in the middle of its one parallel to the length and the other parallel to the breadth find the cost of gravelling them at rupees 1.20 per square metre​

Answer 1

area of long strip = 80*10 or 800 m^2

area of shorter strip = 60(10) = 600 m^2

total = 1400 m^2

BUT, we counted the intersection twice

so we subtract 10(10) or 100 m^2

are of the two "rmads" is 1300 m^2

cost = 1.2(1300)

= 1560 units of money