A,B,C,D,E can do a piece of work in 5,6,7,8,9 days respectively. how many days are requierd to do 3

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14 Jul 2011 work with best effort

A,B,C,D,E can do a piece of work in 5,6,7,8,9 days respectively. how many days are requierd to do 3 times more work if all are doing work with their best effort? (approx)

OPtion

1) 1
2) 3
3) 2
4) 5
5) 4
6) 7
7) 6
8) 9
9) 8
10) none of these

Solution

1 day work of all the five together are = 1/5 + 1/6 + 1/7 + 1/8 + 1/9
= 1879/2520
So days required to do 3 times more work = (2520/1879)*3

= 4.02 days
approx 4 days

Correct Option: 5 Best Solution (5)

~Sandeep~   12 years AGO

3/(1/5 + 1/6 + 1/7 + 1/8 + 1/9) = 4.0234 = ~ 4 (Option 5)

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Aparajita Chowdhury   12 years AGO

if they work together then
(1/5+1/6+1/7+1/8+1/9)=1879/2520 is done in 1 day
so,1(whole)is done in 2520/1879 days
then 3 times more is done in (2520*3)/1879 days
that means 4.02 days=4 days(approx)
so,option 5 is correct.

Like? Yes (4) | No   

abhilash   12 years AGO

If all the persons combinely done the work,the work will be finished in 1/(1/5+1/6+1/7+1/8+1/9)=1.33(app.).
so, the days required to do 3 times more work if all are doing work with their best effort is
3*1.33=4(appr.)

Like? Yes (4) | No (1)  

swetha   12 years AGO

the work done by A,B,C,D,E in one day is 1/5,1/6,1/7,1/8,1/9 respectively
if all work together they can do work in one day as
1/5+1/6+1/7+1/8+1/9=0.74
inverse gives the total number of days if all work together i.e 1.34 days
to work three times more than before it is 1.34*3=4.02
approximately it is 4 days

Like? Yes (3) | No   

Datla Kanthi   12 years AGO

They can complete in 4.023 days appx so option 5

Like? Yes (2) | No