Question

prakash takes an hour to distribute news paper in a block of apartment while his two friends take 80 minutes to do same work individually. if all the three distributive news papers in 2 such blocks of apartment. howll long would they take?

Answer 1

let distributing newspaper in one apartment be one unit of work . so efficiency of prakash =1/60 , friend 1 =1/80 , friend 2 =1/80 for 1 apartment , if all three distributes simultaneously, E = 1/60+1/80+1/80 = 1/24 so all three will take 24 minutes to distribute newspapers in one apartment. twice of this time will be required to distribute newpaper in 2 apartments =24*2 = 48minutes.

Answer 2

It will take 48 minutes .

GIVEN

Minutes taken by Prakash to deliver newspaper in 1 block = 60 minutes.

Minutes taken by his two friends individually = 80 minutes.

TO FIND

Minutes taken by all three of them to deliver the news paper in 2 blocks.

SOLUTION

We can simply solve the above problem as follows;

We know that,

Work = Efficiency × Time.

Let delivering news paper in 1 block = 1 unit of work.

Therefore.

Efficiency of Prakash = 1/60

Similarly,

Efficiency of Friend 1 = 1/80

Efficiency of Friend 2 = 1/80

Let the time taken by 3 friends to deliver newspaper in 2 blocks be x minutes

$(\frac{1}{60} + \frac{1}{80} + \frac{1}{80} ) \times x = 2$

$\frac{4x + 3x + 3x}{240} = 2$

10x = 480

x = 480/10 = 48 minutes.

Hence,It will take 48 minutes .

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