A flagstaff 17.5 m high casts a shadow of length 40.25 m. The height of the building, which casts a shadow of length 28.75 m under similar conditions will be:

Question: A flagstaff 17.5 m high casts a shadow of length 40.25 m. The height of the building, which casts a shadow of length 28.75 m under similar conditions will be:

[A].

10 m

[B].

12.5 m

[C].

17.5 m

[D].

21.25 m

Answer: Option B

Explanation:

Let the height of the building x metres.

Less lengthy shadow, Less in the height (Direct Proportion)

40.25 : 28.75 :: 17.5 : x       40.25 x x = 28.75 x 17.5

x =	28.75 x 17.5
	40.25

x = 12.5