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

Time taken by Henry and Rachel = 9 days ---- (1)
Time taken by Rachel and Anna = 10 days ---- (2)
Time taken by Anna and John = 300% x 9 = 27 days ---- (3)

(1) + (2) + (3)
Henry + Rachel + Rachel + Anna + Anna + John → 9 + 10 + 27 = 46 days
Henry + 2 (Rachel + Anna) + John → 46 days
Henry + John + 2 x 10 → 46 days
Henry + John → 46 - 20 = 26 days

More days to complete the project for Henry and John compared to Rachel and Anna
= 26 - 10
= 16

Answer(s): 16