Question

Two cross roads, each of width 2.5 m, run at right
angles through the centre of a rectangular park of
length 75 m and breadth 35 m parallel to its sides.
The cost of constructing the roads at the rate of
Rs. 160 per 4 m2 is
(1) rs. 43000
(2) rs. 1,72,000
(3) rs. 10750
(4) rs. 8750

Answer 1

Length of the 1st cross road parallel to the length = 70 m
Breadth of the 1st cross road parallel to the length = 5 m

Area of the 1st cross road = 70*5 

= 350 sq m

Length of the 2nd cross road parallel to the breadth = 45 m
Breadth of the 2nd cross road parallel to the breadth = 5 m

Area of the 2nd cross road = 45*5 

= 225 sq m

Area of the common part of the 2 cross roads with width 5 m that lies at the center of the rectangular park = 5*5
 
= 25 sq m

Area of the 2 cross roads = Area of the 1st cross road + Area of the 2nd cross road - Common area

⇒ (350 + 225) - 25

⇒ 575 - 25 

= 550 sq m

Cost of constructing the roads = Rs. 105 sq m

Total cost of constructing the road = 550*105

= Rs. 57750

hope it help you