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

• consider the right angle triangle.. vertical distance is 17.5 mts..shadow falls on ground implies horizontal distance is 40.25...let A be angle between them...tanA=17.5/40.25 second case also similar conditions he given..implies A must be same...let X be height of building..implies tanA =X/28.75..
  therefore 17.5/40.25=X/28.75 ans is X=12.5m
  
• 12 years agoHelpfull: Yes(5) No(1)
• shadow of length 40.25 m = 17.5 m
  high shadow of length 1 m = 17.540.25 m
  high shadow of length 28.75 m = 28.75×17.540.25 m high = 12.5 m high
• 8 years agoHelpfull: Yes(0) No(0)
• Let the required height be x m
  17.5/40.25 =x/28.75
  =>x=12.5
  hence reqd. height of building= 12.5m
• 8 years agoHelpfull: Yes(0) No(0)
• The ans is 12.5m
  By unitary method.
  If 40.25m is the length of the shadow produced by a 17.5m high flagstaff,
  then a 28.75m length shadow will be produced by (28.75*17.5)/40.25
• 8 years agoHelpfull: Yes(0) No(0)