Question

If a 1.5 m tall girl stands at a distance of 3 m from a lamp-post and casts a shadow of length 4.5 m on the ground, then the height of the lamp-post is

(a) 1.5 m

(b) 2 m

(c) 2.5 m

(d) 2.8 m

Answer 1

Let AB be the lamp post and CD =1.5 m be the girl.

The given information can be represented as

Here, shadow of girl is DE = 4.5 m and BD = 3 m.

In ΔCDE,

In ΔABE,

Therefore, height of the lamp post is 2.5 m

Hence the correct option is .