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

area of road that is parallel to lengh

= 80x10= 800 sq m
area of road that is parallel to breadth = 60 x 10 = 600 sq m
Area of two road = (800+600-100)
=1300 sq m
cost at 1 sq m = 1.20
cost at 1300 sq m = 1.2 x 1300
= RS.1560

thanks you !!!

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

Now I showed you how to do one by subtracting rectangles. You do this one.

answer is 1560

To find the cost of graveling the roads, we need to calculate the area of the roads and then multiply it by the cost per square meter.

Let's start by finding the area of each road:

Parallel road length:
The length of the rectangular lawn is 80m, and the road running parallel to the length has a width of 10m. Therefore, the length of the road is also 80m.

Area of parallel road length = Length × Width = 80m × 10m = 800 square meters

Parallel road breadth:
The breadth of the rectangular lawn is 60m, and the road running parallel to the breadth has a width of 10m. Therefore, the length of the road is also 60m.

Area of parallel road breadth = Length × Width = 60m × 10m = 600 square meters

Now, let's calculate the total area by adding the areas of the two roads:

Total area = Area of parallel road length + Area of parallel road breadth
Total area = 800 square meters + 600 square meters = 1400 square meters

Finally, we can find the cost of graveling the roads by multiplying the total area by the cost per square meter:

Cost of graveling = Total area × Cost per square meter
Cost of graveling = 1400 square meters × ₹1.20/square meter

Now, performing the calculation:

Cost of graveling = ₹1680

Therefore, the cost of graveling the two roads is ₹1680.