Question

Anu covers some distance at 4 km/hr and the rest at 6 km/hr. If the average speed for the entire journey is 5 km/hr and total distance covered is 50 km, then how much distance (in km) is covered at 4 km/hr?

Answer 1

Answer:

20 km distance (in km) is covered by Anu at 4 km/hr

Answer 2

Answer:

The distance covered at 4km/hr is 30km.

Explanation:

Given that,

Anu covers some distance at 4km/hr and the rest at 6km/hr. If the average speed for the entire journey is 5km/hr and total distance covered is 50km.

Let the distance covered with a speed of 4km/hr be x km and

The distance covered with a speed of 6km/hr be y km.Therefore,

$x+y=50---- > (1)$

Also given,the average speed for entire journey is 5km/hr.Therefore,

$\frac{Total \:distance}{total \:time} =5$

Since time is the ratio of distance to the speed,the total time taken for entire journey is

$(\frac{x}{4} +\frac{y}{6} )hr$

Substituting known values in average speed relation,we get

$\frac{50}{(\frac{x}{4} +\frac{y}{6} )} =5\\= > (\frac{x}{4} +\frac{y}{6} )=10= > 3x+2y=120-- > (2)$

Solving equations 1 and 2,we get the solution as

$x=30,y=20$

Therefore,the distance covered at 4km/hr is found to be 30km.

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