If Charlotte and Sebastian work together on a project, they will complete it in 10 days. If Sebastian were to work with Stella on the same project, they will take a day longer. If Stella and Henry work together, they will take 180% more time than Charlotte and Sebastian. If Charlotte and Henry were to work together, how many more days will they take to complete the project compared to Sebastian and Stella working together?
Time taken by Charlotte and Sebastian in percent = 100%
Time taken by Stella and Henry = 100% + 180% = 280%

Time taken by Charlotte and Sebastian = 10 days ---- (1)
Time taken by Sebastian and Stella = 11 days ---- (2)
Time taken by Stella and Henry = 280% x 10 = 28 days ---- (3)

(1) + (2) + (3)
Charlotte + Sebastian + Sebastian + Stella + Stella + Henry → 10 + 11 + 28 = 49 days
Charlotte + 2 (Sebastian + Stella) + Henry → 49 days
Charlotte + Henry + 2 x 11 → 49 days
Charlotte + Henry → 49 - 22 = 27 days

More days to complete the project for Charlotte and Henry compared to Sebastian and Stella
= 27 - 11
= 16

Answer(s): 16