If Jacob and Owen work together on a project, they will complete it in 10 days. If Owen were to work with Hannah on the same project, they will take a day longer. If Hannah and Harris work together, they will take 90% more time than Jacob and Owen. If Jacob and Harris were to work together, how many more days will they take to complete the project compared to Owen and Hannah working together?
Time taken by Jacob and Owen in percent = 100%
Time taken by Hannah and Harris = 100% + 90% = 190%

Time taken by Jacob and Owen = 10 days ---- (1)
Time taken by Owen and Hannah = 11 days ---- (2)
Time taken by Hannah and Harris = 190% x 10 = 19 days ---- (3)

(1) + (2) + (3)
Jacob + Owen + Owen + Hannah + Hannah + Harris → 10 + 11 + 19 = 40 days
Jacob + 2 (Owen + Hannah) + Harris → 40 days
Jacob + Harris + 2 x 11 → 40 days
Jacob + Harris → 40 - 22 = 18 days

More days to complete the project for Jacob and Harris compared to Owen and Hannah
= 18 - 11
= 7

Answer(s): 7