Question

A and B working together can finish a woro in 12 days. When A does half of the work and the other half is done by B then it gets completed in 25 days.
Then what is the difference in time taken when they work alone.?​

Answer 1

Step-by-step explanation:

1. two members did the work in 25 days
2. so if one man alone complete in 25 days only

Answer 2

Answer:

Working together A and B will complete

1A+1B=112th of the job in a day ...(1)

Let A take 'A' days to complete the job. Therefore, she will take A2 days to complete half the job.

Similarly, B will take B2 days to complete the other half of the job.

If A starts the work, completes one half and leaves and then B takes over and completes the other half,

A2+B2=25 or A+B=52 ...(2)

Solving for (1 ) and (2), we get 150−B+18−112

(Substituting A = 50 - B in eqn (1)

50(50−B)B=112 or 50B−B2=600 or B2−50B+600=0 or (B−20)(B−30)=0 or B = 20 or B = 30.

If B = 20, then A = 30 and if B = 30, then A = 20.

As B is more efficient than A, she will take lesser time to complete the job. Therefore, B will take 20 days.