A rectangular lawn of length 200m by 120m has two roads running along

IMO: C


Area of the road parallel to the length of the rectangular lawn = 200*5 = 1000 sq m
Area of the road parallel to the breadth of the rectangular lawn = 120*5 = 600 sq m
Area of the intersection of the two perpendicular roads = 5*5 = 25 sq m

Since we calculated the intersection road area twice( once while calculating along length and again while calculating along breadth), we need to subtract from the total sum once to make it even.

Thus area of the paths = 1000+600-25 = 1575 sq m

area of 1st road = (5*120) = 600
area of 2nd road = (5*200) = 1000
area common = (5*5) = 25

thus, net area of roads = 600 + 1000 - 25 = 1575

Ans. = C

Width of roads=5m
Length of lawn=200 m
Breadth of lawn=120 m
Area of roads= Area of road along length+area of road along breadth-common area
=(200*5)+(120*5)-(5*5)
=1600-25=1575
Answer C

Width of the road running along the length = 5m, so length = 200m. -> Area = 5*200 = 1000 m^2

Width of the road running along the width = 5m, so length = 120m. -> Area = 5*120 = 600 m^2.

Area of intersection = 5*5 = 25 m^2.

Total area covered by the two roads = 1000+600-25 = 1575 m^2. Ans (C).

Ans: C

solution: two roads running along the center means [ + ] kind of structure.
so we need to reduce the 5*5 box from the total.
so 200*5 + 120*5 - 5*5 = 1575

Hi All,

This question is a bit oddly worded, but the 'intent' is to see whether you 'double-count' the overlapping space or not (the part that is covered by BOTH the roads in the 'corner' of the rectangle).

To start, we have a rectangle that is 200m x 120m. There's a 5m wide road that runs the entire length of the rectangle and one that runs the entire width of the rectangle. The areas of the individual roads are...

(5m)(200m) = 1000 m^2
(5m)(120m) = 600 m^2

However, these two roads 'overlap', creating a (5m)(5m) = 25 m^2 space in the corner in which they meet. That space is included in BOTH of those calculations though, so we have to remove one iteration of it. This leaves us with a total 'road area' of...

1000 + 600 - 25 = 1575 m^2

Final Answer:

GMAT assassins aren't born, they're made,
Rich

Area of Road A + Area of Road B - Overlap in the Center = 600 + 1000 - 25 (5 * 5 for the width of the respective roads) = 1575