Problema Solution

Working together, Lauren and David can do a job in 4 hours. Working alone it would take David twice as long as Lauren to do the job. How long would it take Lauren to do the job alone?

Answer provided by our tutors

let time taken byLauren = x hrs & by David  =2x hrs

1/x + 1/2x = 1/4

3/2x = 1/4

x = 4*3/2 = 6

time taken by Lauren = 6 hrs