Question

please answer if you know correctly ​

Answer 1

Given :-

• Total distance to be travelled = 6 km
• There is a point namely Sangam which is 3 km from starting point .
• While going to Sangam average speed = 1.5 km / hr
• While coming back speed = Half of the initial speed .

To find

• How much time does this journey require ?

• For returning back at 12 noon , when should Ram start his journey?

Solution

Case 1st ( Going to Sangam )

Time required for going to Sangam = $\frac{Total\: distance}{Average\:Speed}$

→ Total distance = 3km

→ Average speed = 1.5 km / hr

$\implies \: time \: = \frac{3}{ \frac{15}{10} }$

$\implies \: \frac{30}{15} hr$

→ 2 hours .

So Ram will take 2 hours to reach Sangam .

Case 2nd ( Coming back from Sangam)

→ Formula of time is same as of case 1st .

→ Distance = 3 km

→ Speed = 1.5/2 km/ hr

$\implies \: \frac{15}{20 } \: km \: per \: hour$

$time \: = \frac{3 \times 20}{15}$

→ Time = $\frac{60}{15}$

→ Time = 4 hours .

So Ram will take 4 hours for coming back from Sangam .

Total time taken = Time in case 1st + time in case 2nd

→ 2 hours + 4 hours

→ 6 hours .

Answer 1st is 6 hours .

Now Ram has to reach at 12 noon . So he should start his journey 6 hours before 12 noon .

→ 12 : 00 - 6 hours

→ 6: 00 am

Answer 2nd is Ram should start his journey at 6 am

Answer 2

$\underline\mathit\green{Given...}$

✰✰ total distance to be travelled = 6 km

✰✰ the distance between the Sangam point and the starting point = 3 km

✰✰ the average speed during going to sangam point = 1.5 km/h

✰✰ the average speed during coming from sangam point = half of 1.5 km/h

$\underline\mathit\green{To\:find...}$

★★ total time taken during this journey...

★★ after returning at 12 noon, when should ram start his journey...

$\huge\underline\mathit\blue{SoLution...}$

$\underline\mathit\red{In\:case\: 1...}$

we know that...

Time = $\dfrac{Distance}{Speed}$

So,...

total distance = 3km

average speed = 1.5 km/h

Time = $\dfrac{Total\:distance}{Average\:time}$

Time = $\dfrac{3}{1.5}$

Time = $\dfrac{30}{15}hr$

• $\boxed{\green{\underline\textbf{= 2 hr}}}$

So, Ram will take 2 hrs to reach the Sangam point...

$\underline\mathit\red{In\:case\: 2...}$

Time = $\dfrac{Distance}{Speed}$

Distance = 3 km

speed = $\dfrac{1.5}{2}$

speed = $\dfrac{15}{20}$

Time = $\dfrac{Total\:distance}{Average\:time}$

Time = $\dfrac{3\times20}{15}$

Time = $\dfrac{60}{15}$

• $\boxed{\green{\underline\textbf{= 4 hr}}}$

So, Ram will take 4 hrs to coming back from the Sangam point...

✰✰ Now, we have to calculate total time taken during the journey...

total time = time taken in çase 1 + time taken in case 2

===> 2 hrs + 4 hrs

• $\boxed{\green{\underline\textbf{= 6 hr}}}$

Now, Ram has to reach at 12 noon...

So, he should start his journey 6 hours before 12 noon...

• 12 : 00 - 6 : 00
• 6 : 00

Therefore, Ram should start his journey at 6 am...