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

Time taken by Nathan and Ellie = 10 days ---- (1)
Time taken by Ellie and Jeremiah = 11 days ---- (2)
Time taken by Jeremiah and Joshua = 190% x 10 = 19 days ---- (3)

(1) + (2) + (3)
Nathan + Ellie + Ellie + Jeremiah + Jeremiah + Joshua → 10 + 11 + 19 = 40 days
Nathan + 2 (Ellie + Jeremiah) + Joshua → 40 days
Nathan + Joshua + 2 x 11 → 40 days
Nathan + Joshua → 40 - 22 = 18 days

More days to complete the project for Nathan and Joshua compared to Ellie and Jeremiah
= 18 - 11
= 7

Answer(s): 7