A flagstaff 17 5 m high casts a shadow of length 40 25 m What will be the height of a building which...........

Explanation:

Let the required height of the building be x meter

More shadow length, More height(direct proportion)

Hence we can write as
(shadow length) 40.25 : 28.75 :: 17.5 : x
⇒ 40.25 × x = 28.75 × 17.5
⇒ x = 28.75 × 17.5/40.25
= 2875 × 175/40250
= 2875 × 7/1610
= 2875/230
= 575/46
= 12.5 cm