Question

pranali and prasad started walking to the east and to the north respectively.from the same point and at the same speed after 2 hours distance between them was 15|√2

Answer 1

Hello Dear.

Question is little bit incomplete. In the Question it is not exactly given what we have to find. So, as per as my Research, In the Question, we can find the Distance Covered by the Pranali and the Prasad and there speed in covering the Distance.
Also, no units is given in the question for distance, so assuming the km.

Now, Refers the attachment for the Question.

Distance between Pranali and Prasad after 2 hours = 15/√2 km.
 = 15/√2 × √2/√2
 = (15√2)/2
 = 7.5√2 km.

Let the Speed of the Pranali and the Prasad be x km/hr.
[Since there speed is same.]


Now, For Pranali,
Time = 2hrs.
Distance = BC.

∵ Speed = Distance/Time
∴ Distance(BC) = Speed × Time.
∴ BC = x × 2
⇒ BC = 2x

For Prasad,
Time = 2 hrs.
Distance = AB

∴ Distance(AB) = x × 2
    = 2x

We can see that Distance covered by both of them is similar,

Now, From the attachment,

Applying Pythagoras Theorem,

   AC² = AB² + BC²
⇒ (7.5√2)² = (2x)² + (2x)²
⇒ 112.5 = 4x² + 4x²
⇒ 8x² = 112.5
⇒ x² = 112.5/8
⇒ x² = 14.0625
⇒ x = √14.0625
⇒ x = 3.75 

∴ Distance covered by Pranali and Prasad is 3.75 km.

Now, For the Speed,

∵ Speed = Distance/Time
∴ x = 3.75/2
∴ x = 1.875 km/hr.


Hence, Speed of the Pranali and the Prasad is 1.875 km/hr.


Hope it helps.