​A person 1.75 m tall casts a 2 m shadow. At the same instance a lamp - post casts a shadow of 6.4 m. The height of the lamp-post is

Correct option is A

Given; 

​Person Height = 1.75m,

Person Shadow = 2m, 

post casts shadow = 6.4 

Formula Used: 

$$\frac{\text{Person Height}}{\text{Person Shadow}} = \frac{\text{post casts height}}{\text{post casts shadow}}$$ 

Solution:  

Let the Lamp Post height is h

$$\frac{1.75}2=\frac{h}{6.4}$$  

$$\text{h}= \frac{1.75\times6.4}2$$​

h = 1.75 $$\times$$ 3.2

h = 5.6 m 

Thus, the Lamp post height is 5.6 m