If Samantha and Roshel work together on a project, they will complete it in 10 days. If Roshel were to work with Stella on the same project, they will take a day longer. If Stella and Layla work together, they will take 80% more time than Samantha and Roshel. If Samantha and Layla were to work together, how many more days will they take to complete the project compared to Roshel and Stella working together?
Time taken by Samantha and Roshel in percent = 100%
Time taken by Stella and Layla = 100% + 80% = 180%

Time taken by Samantha and Roshel = 10 days ---- (1)
Time taken by Roshel and Stella = 11 days ---- (2)
Time taken by Stella and Layla = 180% x 10 = 18 days ---- (3)

(1) + (2) + (3)
Samantha + Roshel + Roshel + Stella + Stella + Layla → 10 + 11 + 18 = 39 days
Samantha + 2 (Roshel + Stella) + Layla → 39 days
Samantha + Layla + 2 x 11 → 39 days
Samantha + Layla → 39 - 22 = 17 days

More days to complete the project for Samantha and Layla compared to Roshel and Stella
= 17 - 11
= 6

Answer(s): 6