Question

A saree is 5m long and 1.3m wide.A border of width 25cm is printed along its sides.Find the cost of printing the border at Rs.1 per 10 cm2.

Answer 1

Here we go.

l=500cm
w=130cm

now the area of entire saree is A= 500*130=65000 cm²

now to find the area of the border, we should subtract the area of the middle of the saree from the whole area. Firstly, let's find the area of the middle part of saree,  where length= 500- 25 - 25 =450 cm and width= 130 - [25*2] = 80cm.
so, the area of the middle part = B = 450*80 = 36000 cm²

[you can check the diagram I drew if you get confused]

that means, the area of the border of the sari is A-B= 65000-36000=29000cm²

now the cost is Rs.1 per 10 cm², which means for 29000 cm² it is...
➣ 29000/10 = 2900 Rs.

Hope it helped.  

Answer 2

length of saree = 5 m = 500 cm
Breadth of saree = 1.3 m = 130 cm
Area of saree with border = 500×130 = 65000 cm²

Now, length of saree without border = 500 - (25+25) = 450 cm
Breadth of saree without border = 130 -(25+25) = 80 cm
Area without border = 450×80 = 36000 cm²

Area of border = 65000 - 36000 = 29000 cm²

Cost = (29000/10)×1 = Rs 2900