Question

x,y and z take 20, 30 and 60 days respectively to complete a job independently. they set out to complete a job together . however y leaves after 4 days and z leaves after another 6 days . how many more days will it take for x alone to complete the job now?

Answer 1

(x+y+z)4 +(x+z)6 +x(k)=1
(1/20+1/30+1/60)4 +(1/20+1/60)6 +(1/20)k =1
(3+2+1/60)4 +(3+1/60)6 +k/20=1
6×4/60 +4×6/60 +k/20=1
24/60 +24/60+k/20=1
48/60 +k/20=1
k/20= 1-48/60
k/20=12/60
k=12×20/60
k=12/3
k=4days
x complete in 4 days

Answer 2

x alone  will take  4 days more to complete the job.

Step-by-step explanation:

20, 30 and 60 days are taken by x,y and z respectively to complete a job independently.

y leaves after 4 days.

z leaves after another 6 days.

To Find:

The number of  more days will it take for x alone to complete the job now.

Solution:

As given-20, 30 and 60 days are taken by x,y and z respectively to complete a job independently.

When All (x,y&z) worked together, they can complete work in 10 days.

4 days they(x,y&z) all worked together.

40% of work was completed.

When x & z work together they can complete all work in 15 days.

So in another 6 days they will complete 40% of work .

Rest 20% work to be completed by x.

As given x completes whole work in 20 days,

so 20% of work will be completed by x in 4 days.

Thus, x alone  will take  4 days more to complete the job.

PROJECT CODE#SPJ3