5 m long ladder is leaning against a wall and it reaches the wall at a point 3 m high. If the foot of the ladder is moved 2.6 m towards the wall then the distance by which the top of the ladder slides upwards on the wall is:

Correct option is A

Given:

​Length of ladder = 5 m 

Formula Used:

​$$\text{base}^2 + \text{height}^2 = \text{hypotenuse}^2$$​​

Solution: 

According to the question,

Distance from the wall to the foot of the ladder =$$\sqrt{5^2−3^2}$$​=4 m

Now it become 4 - 2.6 = 1.4 m

So height  =$$\sqrt{5^2−1.4^2}=\sqrt{25−1.96}$$​​

=>= 4.8

So ladder slide upwards by 4.8 - 3 = 1.8 m