15. Akbar and Birbal start towards each other from their homes, 15 km apart, at 10 a.m. Akbar walks at a constant speed of 4 km/h, while Birbal walks at a constant speed of 6 km/h. When will they meet?

6. In the previous question, after Akbar and Birbal meet, they chat for half an hour and then leave for their respective homes. At what time will they reach home?

A. 1:30 pm



Answer :

### Solution:

Let's address each part of the question step by step.

#### Part 1: When will Akbar and Birbal meet?

Given:
- Distance apart = 15 km
- Speed of Akbar = 4 km/h
- Speed of Birbal = 6 km/h

To determine the time they will meet, we need to calculate the relative speed when both walk towards each other.

1. Calculate the total relative speed:
[tex]\[ \text{Total speed} = \text{Speed of Akbar} + \text{Speed of Birbal} = 4 \text{ km/h} + 6 \text{ km/h} = 10 \text{ km/h} \][/tex]

2. Calculate the time taken to meet:
[tex]\[ \text{Time to meet} = \frac{\text{Distance apart}}{\text{Total speed}} = \frac{15 \text{ km}}{10 \text{ km/h}} = 1.5 \text{ hours} \][/tex]

3. Convert the time to hours and minutes:
[tex]\[ 1.5 \text{ hours} = 1 \text{ hour} + 0.5 \text{ hour} = 1 \text{ hour} + 30 \text{ minutes} \][/tex]

4. Calculate the meeting time if they start at 10:00 am:
[tex]\[ 10:00 \text{ am} + 1 \text{ hour} + 30 \text{ minutes} = 11:30 \text{ am} \][/tex]

Thus, Akbar and Birbal will meet at 11:30 am.

#### Part 2: At what time will Akbar and Birbal reach home after chatting?

Given:
- They chat for 30 minutes after they meet.
- Both walk back home at their respective speeds.

1. Calculate the time they start walking back home:
[tex]\[ \text{Meeting time} = 11:30 \text{ am} \][/tex]
[tex]\[ \text{Chatting time} = 30 \text{ minutes} \][/tex]
[tex]\[ \text{Start walking back home} = 12:00 \text{ pm} (noon) \][/tex]

2. Calculate the time taken by Birbal to walk home:
- The distance for each to their home from meeting point is half of the initial distance:
[tex]\[ \text{Distance for Birbal} = \frac{15 \text{ km}}{2} = 7.5 \text{ km} \][/tex]
- Birbal's speed = 6 km/h:
[tex]\[ \text{Time to walk home} = \frac{7.5 \text{ km}}{6 \text{ km/h}} = 1.25 \text{ hours} = 1 \text{ hour} + 15 \text{ minutes} \][/tex]
- Time when Birbal reaches home:
[tex]\[ 12:00 \text{ pm} + 1 \text{ hour} + 15 \text{ minutes} = 1:15 \text{ pm} \][/tex]

3. Calculate the time taken by Akbar to walk home:
- The distance for Akbar is the same, 7.5 km:
[tex]\[ \text{Distance for Akbar} = \frac{15 \text{ km}}{2} = 7.5 \text{ km} \][/tex]
- Akbar's speed = 4 km/h:
[tex]\[ \text{Time to walk home} = \frac{7.5 \text{ km}}{4 \text{ km/h}} = 1.875 \text{ hours} = 1 \text{ hour} + 52.5 \text{ minutes} \][/tex]
- Time when Akbar reaches home:
[tex]\[ 12:00 \text{ pm} + 1 \text{ hour} + 52.5 \text{ minutes} = 1:52.5 \text{ pm} \approx 1:53 \text{ pm} \][/tex]

Thus, Birbal will reach home at 1:15 pm and Akbar will reach home at approximately 1:53 pm.