Question

Arjun can complete a project in 20 days and aryan can do it in 25 days. they start working together but due to some reason a project after 2 days. in how many days in how many days will the project will be completed?

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Answer 1

Answer:

22.5

Step-by-step explanation:

work done by both in 1 day= 1/20+1/25=4+5/100=9/100

work done in 2 days =9/100×2=9/50

work needs to be completed by arjun only=1-9/50=41/100

work done by ayan in 1 day=2/50

work done by arjun= 41/50×50÷2=20.5

days = 20.5+2=22.5

Answer 2

Given:

A task was completed by Arjun in 20 days and the same task was completed by Aryan in 25 days.

Arjun left work after 2 days.

To find:

The number of days required to complete the task.

Solution:

The L.C.M of 20 and 25 is 100. So, 100 units in the total work.

The work completed by Arjun in one day is,

$\frac{100}{20}=5 units$

The work completed by Aryan in one day is,

$\frac{100}{25}=4 units$

The work completed by Arjun and Aryan in two days is,

$2days=2(5+4)\\=2\times9\\=18 units$

After 2 days, the work left to be completed is,

$100-18=82 units$

But after 2 days of working together, Arjun has left the work. So, Aryan will do the leftover work.

Aryan does 4 units of work in a day, so,  82 units of work will be completed in,

$\frac{82}{4}=2\frac{2}{4}days$

Thus, the project will be completed in $2\frac{2}{4}days$ after Aujan left the work.