If Riordan and Isabella work together on a project, they will complete it in 9 days. If Isabella were to work with Risa on the same project, they will take a day longer. If Risa and Samuel work together, they will take 200% more time than Riordan and Isabella. If Riordan and Samuel were to work together, how many more days will they take to complete the project compared to Isabella and Risa working together?
Time taken by Riordan and Isabella in percent = 100%
Time taken by Risa and Samuel = 100% + 200% = 300%

Time taken by Riordan and Isabella = 9 days ---- (1)
Time taken by Isabella and Risa = 10 days ---- (2)
Time taken by Risa and Samuel = 300% x 9 = 27 days ---- (3)

(1) + (2) + (3)
Riordan + Isabella + Isabella + Risa + Risa + Samuel → 9 + 10 + 27 = 46 days
Riordan + 2 (Isabella + Risa) + Samuel → 46 days
Riordan + Samuel + 2 x 10 → 46 days
Riordan + Samuel → 46 - 20 = 26 days

More days to complete the project for Riordan and Samuel compared to Isabella and Risa
= 26 - 10
= 16

Answer(s): 16