Question

A rectangular lawn 80m*60m has two roads each 10m wide running in the middle of it ,one parallel to the length and other parallel to the breadth .Find the cost of gravelling them at ₹1.20 per sq metre.

Answer 1

Cost rs. 1560
Total Sq m=1300

Answer 2

ar(rectangle)=l*b
                    =80*60
                    =4800
ar(2 roads)=ar(1road+another road -central square junction)
                  =80*10+60*10-10*10
                  =800+600-100
                  =1300
ar(gravelling)=ar(rectangle-roads)
                    =4800-1300
                    =3500
3500*1.2=cost
              =2200