Question

7 Sonu and Monu travel from point P to Q. a distance of 42 km, at 6 km/h
and 8 km/h, respectively. Monu reaches Q first and returns immediately
and meets Sonu at R. Find the distance from points P to R.​

Answer 1

The distance from points P to R is 36 km.​

Step-by-step explanation:

Given:

Here let D = 42 km, a = 12 km/h  and b = 16 km/h

According to the formula,  distance travelled by

$A= PR=2D\times(\frac{a}{a+b} )$

              $=2\times 42\times(\frac{12}{12+16} )$

              $=2\times 42\times(\frac{12}{28} )$

              $=42\times(\frac{6}{7} )$

              $= 6 \times 6$

               = 36 km.

Therefore the distance from points P to R is 36 km.​

             

             

Answer 2

Question :- Sonu and Monu travel from point P to Q. a distance of 42 km, at 6 km/h and 8 km/h, respectively. Monu reaches Q first and returns immediately and meets Sonu at R. Find the distance from points P to R.

Solution :-

→ Total distance between P and Q = 42 km .

so,

→ Time taken by Sonu at 6km/h = Distance/speed = 42/6 = 7 hours.

and,

→ Time taken by Monu at 8km/h = Distance/speed = 42/8 = (21/4) hours.

then,

→ In (21/4) hours Sonu covers distance = Time * speed = (21/4) * 6 = (63/2) km .

Now, Sonu is (63/2) km away from P and Monu is at Q .

So,

→ Distance Left to be travelled = 42 - (63/2) = (21/2) km.

given that, Monu return immidately .

therefore,

→ Usual speed of both = 6 + 8 = 14 km/h .

hence,

→ Time taken by them to meet at R = Distance/usual speed = {(21/2) / 14} = (3/4) hours.

∴

→ Distance between P and R = Time for which Sonu travel * his speed = {(21/4) + (3/4)} * 6 = (24/4) * 6 = 6 * 6 = 36 km (Ans.)

Learn more :-

A leak in the body of a ship which can admit 5 units of water in 16 minutes got detected when it is 40km

away from the s...

https://brainly.in/question/26688438

A train starting from a station X was to arrive at a station Y at 6:06 PM. It could travel at 62.5% of its usual

speed a...

https://brainly.in/question/26746228